WorldWideScience

Sample records for heart assist device

  1. Right heart failure post left ventricular assist device implantation.

    Science.gov (United States)

    Argiriou, Mihalis; Kolokotron, Styliani-Maria; Sakellaridis, Timothy; Argiriou, Orestis; Charitos, Christos; Zarogoulidis, Paul; Katsikogiannis, Nikolaos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Tsiouda, Theodora; Tsakiridis, Kosmas; Zarogoulidis, Konstantinos

    2014-03-01

    Right heart failure (RHF) is a frequent complication following left ventricular assist device (LVAD) implantation. The incidence of RHF complicates 20-50% (range, 9-44%) of cases and is a major factor of postoperative morbidity and mortality. Unfortunately, despite the fact that many risk factors contributing to the development of RHF after LVAD implantation have been identified, it seems to be extremely difficult to avoid them. Prevention of RHF consists of the management of the preload and the afterload of the right ventricle with optimum inotropic support. The administration of vasodilators designed to reduce pulmonary vascular resistance is standard practice in most centers. The surgical attempt of implantation of a right ventricular assist device does not always resolve the problem and is not available in all cardiac surgery centers.

  2. A monitoring device for pressurised-air-driven diaphragm-based artificial heart assist devices

    NARCIS (Netherlands)

    Hoeben, F.P.; Hoeben, F.P.; de Mul, F.F.M.; Stokkink, J.S.D.; Stokkink, H.S.D.; Koelink, M.H.; Koelink, M.H.; Greve, Jan

    1992-01-01

    A non-invasive device has been developed to monitor the diaphragm position and the blood flow in artificial heart assist devices equipped with a pressurised-air-driven diaphragm. Light scattering from the diaphragm is used as a mechanism for measuring. Information about the position of several

  3. Ventricular assist device use in congenital heart disease with a comparison to heart transplant.

    Science.gov (United States)

    Miller, Jacob R; Eghtesady, Pirooz

    2014-09-01

    Despite advances in medical and surgical therapies, some children with congenital heart disease (CHD) are not able to be adequately treated or palliated, leading them to develop progressive heart failure. As these patients progress to end-stage heart failure they pose a unique set of challenges. Heart transplant remains the standard of care; the donor pool, however, remains limited. Following the experience from the adult realm, the pediatric ventricular assist device (VAD) has emerged as a valid treatment option as a bridge to transplant. Due to the infrequent necessity and the uniqueness of each case, the pediatric VAD in the CHD population remains a topic with limited information. Given the experience in the adult realm, we were tasked with reviewing pediatric VADs and their use in patients with CHD and comparing this therapy to heart transplantation when possible.

  4. Institutional Cost Comparison Between Heart Transplants and Left Ventricular Assist Device Implantations.

    Science.gov (United States)

    Chimanji, Neeraj; Kilic, Arman; Hasan, Ayesha; Higgins, Robert S D; Whitson, Bryan A; Kilic, Ahmet

    2016-12-01

    Increased numbers of end-stage heart failure patients and improved technology have led to increased use of left ventricular assist devices as a viable alternative to heart transplants. Given the current economic climate, we compared costs of heart transplant versus device placement. Medical records of patients who received heart transplants or left ventricular assist devices were cross-referenced with institutional financial data. The device cohort was limited to those receiving durable (not temporary) devices. Index admission, 1-year readmission, and overall 1-year charges were compared using standard statistical methods. Of 184 identified patients with end-stage heart failure surgical therapy, 121 received left ventricular assist devices, 43 had heart transplants, and 20 received left ventricular assist devices as bridge to heart transplant; these latter patients were excluded from our analyses. At index admission, mean charges were $863 433 ± $398 427 for device patients and $725 877 ± $488 685 for transplant patients (P = .05). One-year mean readmission rates were similar (4.65/transplant patient and 4.53/device patient; P = .94), with corresponding 1-year survival rates of 87.8% and 78.0% (P = .04). Total readmission charges during year 1 were $169 732 ± $242 366 for device patients and $201 682 ± $297 565 for transplant patients (P = .08), with corresponding overall charges at 1 year of $1 029 732 ± $450 498 and $927 559 ± $562 404 (P = .49). During the first year, heart transplant and left ventricular assist device placement have similar costs. Initial index admission costs seem to favor heart transplant, with device pump costs accounting for some of the difference. From a 1-year survival perspective, heart transplant may be more effective; however, with lack of suitable donors, left ventricular assist devices are valuable in the armamentarium of advanced heart failure surgical options.

  5. Heart failure - surgeries and devices

    Science.gov (United States)

    ... surgery; HF - surgery; Intra-aortic balloon pumps - heart failure; IABP - heart failure; Catheter based assist devices - heart failure ... problem may cause heart failure or make heart failure worse. Heart valve surgery may be needed to repair or ...

  6. Copeptin in Heart Failure, Post-Left Ventricular Assist Device and Post-Heart Transplantation.

    Science.gov (United States)

    Zabarovskaja, Stanislava; Hage, Camilla; Gabrielsen, Anders; Mellbin, Linda; Lund, Lars H

    2017-02-01

    Heart failure (HF) is associated with pathological activation of arginine vasopressin, measured in plasma by the pre-hormone fragment copeptin. We hypothesised that copeptin is elevated and associated with worse prognosis in HF, and that left ventricular assist device (LVAD) therapy and heart transplantation (HTx) are associated with lower levels of copeptin. We measured copeptin in groups of 49 patients with advanced HF, 13 patients one year post-LVAD and 22 patients one year post-HTx and correlated with clinical data and cardiac output. In HF we also assessed the prognostic role of copeptin with Kaplan-Meier analysis and multivariate Cox regression. In HF, median (interquartile range) copeptin was 28 (18-45) pmol/L, after LVAD 16 (6-27) pmol/L, and after HTx 12 (5-20) pmol/L (p overall copeptin was an independent predictor of death, LVAD or HTx (hazard ratio for log copeptin, 3.28 [95% confidence interval: 1.66-6.50], p=0.001). Copeptin was elevated in, and independently predicted prognosis in, HF. Copeptin was progressively lower after LVAD and HTx. This suggests that improvement in cardiac output with LVAD and HTx may induce progressively reduced activation of vasopressin, which may be a marker for the beneficial effects of LVAD and HTx. Copyright © 2016. Published by Elsevier B.V.

  7. Left ventricular assist device therapy in advanced heart failure

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Rogers, Joseph G

    2017-01-01

    Despite improvements in pharmacological therapy and pacing, prognosis in advanced heart failure (HF) remains poor, with a 1-year mortality of 25-50%. While heart transplantation provides excellent survival and quality of life for eligible patients, only a few can be offered this treatment due...

  8. Polymeric heart valves for surgical implantation, catheter-based technologies and heart assist devices.

    Science.gov (United States)

    Bezuidenhout, Deon; Williams, David F; Zilla, Peter

    2015-01-01

    Efficient function and long-term durability without the need for anticoagulation, coupled with the ability to be accommodated in many different types of patient, are the principal requirements of replacement heart valves. Although the clinical use of valves appeared to have remained steady for several decades, the evolving demands for the elderly and frail patients typically encountered in the developed world, and the needs of much younger and poorer rheumatic heart disease patients in the developing world have now necessitated new paradigms for heart valve technologies and associated materials. This includes further consideration of durable elastomeric materials. The use of polymers to produce flexible leaflet valves that have the benefits of current commercial bioprosthetic and mechanical valves without any of their deficiencies has been held desirable since the mid 1950s. Much attention has been focused on thermoplastic polyurethanes in view of their generally good physico-chemical properties and versatility in processing, coupled with the improving biocompatibility and stability of recent formulations. Accelerated in vitro durability of between 600 and 1000 million cycles has been achieved using polycarbonate urethanes, and good resistance to degradation, calcification and thrombosis in vivo has been shown with some polysiloxane-based polyurethanes. Nevertheless, polymeric valves have remained relegated to use in temporary ventricular assist devices for bridging heart failure patients to transplantation. Some recent studies suggest that there is a greater degree of instability in thermoplastic materials than hitherto believed so that significant challenges remain in the search for the combination of durability and biocompatibility that would allow polymeric valves to become a clinical reality for surgical implantation. Perhaps more importantly, they could become candidates for use in situations where minimally invasive transcatheter procedures are used to

  9. Evaluation of the HeartMate II™ left ventricular assist device in obese heart failure patients: effects on weight loss.

    Science.gov (United States)

    Thompson, Keith; Dhesi, Pavittarpaul; Nguyen, David; Czer, Lawrence; Moriguchi, Jamie; Schwarz, Ernst

    2011-01-01

    The purpose of this study is to evaluate the effect on weight loss of the newer generation continuous flow HeartMate II™ left ventricular assist device (VAD) in obese heart failure (HF) patients. We retrospectively reviewed 3-year surgical data from a large heart transplant facility and identified obese patients with advanced heart failure who underwent successful implantation of either the HeartMate XVE(®) or the HeartMate II(®) VAD. For each patient weight and BMI at time of VAD implantation and at 6 months post-operatively were documented. Between group comparison was achieved with Student's T tests. We identified 14 patients who had received the HeartMate XVE™ and 8 who had received the HeartMate II™. At 6 months, patients who received a HeartMate XVE™ demonstrated a significant reduction in mean body weight (249.6 ± 35.4lbs vs. 217.4 ± 20.5 lbs; P<0.05), while patients who received the HeartMate II™ demonstrated no significant change in weight (234.5 ± 41.7 lbs vs. 234.7 ± 43.0lbs; P=0.3). The HeartMate XVE™ results in significant reductions in weight at 6 months in obese patients with heart failure while the HeartMate II does not. Further research is necessary to better understand the effects of VADs on weight loss in obese HF patients.

  10. Heart monitoring using left ventricle impedance and ventricular electrocardiography in left ventricular assist device patients.

    Science.gov (United States)

    Her, Keun; Ahn, Chi Bum; Park, Sung Min; Choi, Seong Wook

    2015-03-21

    Patients who develop critical arrhythmia during left ventricular assist device (LVAD) perfusion have a low survival rate. For diagnosis of unexpected heart abnormalities, new heart-monitoring methods are required for patients supported by LVAD perfusion. Ventricular electrocardiography using electrodes implanted in the ventricle to detect heart contractions is unsuitable if the heart is abnormal. Left ventricular impedance (LVI) is useful for monitoring heart movement but does not show abnormal action potential in the heart muscle. To detect detailed abnormal heart conditions, we obtained ventricular electrocardiograms (v-ECGs) and LVI simultaneously in porcine models connected to LVADs. In the porcine models, electrodes were set on the heart apex and ascending aorta for real-time measurements of v-ECGs and LVI. As the carrier current frequency of the LVI was adjusted to 30 kHz, it was easily derived from the original v-ECG signal by using a high-pass filter (cutoff: 10 kHz). In addition, v-ECGs with a frequency band of 0.1 - 120 Hz were easily derived using a low-pass filter. Simultaneous v-ECG and LVI data were compared to detect heart volume changes during the Q-T period when the heart contracted. A new real-time algorithm for comparison of v-ECGs and LVI determined whether the porcine heartbeats were normal or abnormal. Several abnormal heartbeats were detected using the LVADs operating in asynchronous mode, most of which were premature ventricle contractions (PVCs). To evaluate the accuracy of the new method, the results obtained were compared to normal ECG data and cardiac output measured simultaneously using commercial devices. The new method provided more accurate detection of abnormal heart movements. This method can be used for various heart diseases, even those in which the cardiac output is heavily affected by LVAD operation.

  11. Left ventricular assist device effects on metabolic substrates in the failing heart.

    Directory of Open Access Journals (Sweden)

    Lindsay B Weitzel

    Full Text Available Heart failure patients have inadequate nutritional intake and alterations in metabolism contributing to an overall energy depleted state. Left ventricular assist device (LVAD support is a common and successful intervention in patients with end-stage heart failure. LVAD support leads to alterations in cardiac output, functional status, neurohormonal activity and transcriptional profiles but the effects of LVADs on myocardial metabolism are unknown. This study set out to measure cardiac metabolites in non-failing hearts, failing hearts, and hearts post-LVAD support.The study population consisted of 8 non-ischemic failing (at LVAD implant and 8 post-LVAD hearts, plus 8 non-failing hearts obtained from the tissue bank at the University of Colorado. NMR spectroscopy was utilized to evaluate differences in myocardial energy substrates. Paired and non-paired t-tests were used to determine differences between the appropriate groups.Glucose and lactate values both decreased from non-failing to failing hearts and increased again significantly in the (paired post-LVAD hearts. Glutamine, alanine, and aromatic amino acids decreased from non-failing to failing hearts and did not change significantly post-LVAD. Total creatine and succinate decreased from non-failing to failing hearts and did not change significantly post-LVAD.Measured metabolites related to glucose metabolism are diminished in failing hearts, but recovered their values post-LVAD. This differed from the amino acid levels, which decreased in heart failure but did not recover following LVAD. Creatine and the citric acid cycle intermediate succinate followed a similar pattern as the amino acid levels.

  12. Management issues during HeartWare left ventricular assist device implantation and the role of transesophageal echocardiography

    Directory of Open Access Journals (Sweden)

    Sanjay Orathi Patangi

    2013-01-01

    Full Text Available Left ventricular assist devices (LVAD are increasingly used for mechanical circulatory support of patients with severe heart failure, primarily as a bridge to heart transplantation. Transesophageal echocardiography (TEE plays a major role in the clinical decision making during insertion of the devices and in the post-operative management of these patients. The detection of structural and device-related mechanical abnormalities is critical for optimal functioning of assist device. In this review article, we describe the usefulness of TEE for optimal perioperative management of patients presenting for HeartWare LVAD insertion.

  13. Minimally invasive delivery of a novel direct epicardial assist device in a porcine heart failure model.

    Science.gov (United States)

    McGarvey, Jeremy R; Shimaoka, Toru; Takebayashi, Satoshi; Aoki, Chikashi; Kondo, Norihiro; Takebe, Manabu; Zsido, Gerald A; Jassar, Arminder; Gorman, Joseph H; Pilla, James J; Gorman, Robert C

    2014-01-01

    Despite advances in design, modern ventricular assist device placement involves median sternotomy and cardiopulmonary bypass and is associated with infectious/embolic complications. In this study, we examine the feasibility and function of a novel minimally invasive, non-blood-contacting epicardial assist device in a porcine ischemic cardiomyopathy model. Feasibility was first tested in an ex vivo thoracoscopic trainer box with slaughterhouse hearts. Five male Yorkshire swine underwent selective ligation of the circumflex artery to create a posterolateral infarct Twelve weeks after infarct, all animals underwent left minithoracotomy. A custom inflatable bladder was positioned over the epicardial surface of the infarct and firmly secured to the surrounding border zone myocardium with polypropylene mesh and minimally invasive mesh tacks. An external gas pulsation system actively inflated and deflated the bladder in synchrony with the cardiac cycle. All animals then underwent cardiac magnetic resonance imaging to assess ventricular function. All subjects successfully underwent off-pump placement of the epicardial assist device via minithoracotomy. Ejection fraction significantly improved from 29.1% ± 4.8% to 39.6% ± 4.23% (P porcine ischemic cardiomyopathy model and may provide a safe alternative to currently available ventricular assist device therapies. Further, the technique used for device positioning and fixation suggests that an entirely thoracoscopic approach is possible.

  14. HeartMate II Left Ventricular Assist Device Pump Exchange: A Single-Institution Experience.

    Science.gov (United States)

    Shaikh, Asad F; Joseph, Susan M; Lima, Brian; Hall, Shelley A; Malyala, Rajasekhar; Rafael, Aldo E; Gonzalez-Stawinski, Gonzalo V; Chamogeorgakis, Themistokles

    2017-08-01

    Background  Left ventricular assist devices (LVADs) have revolutionized the treatment of patients with end-stage heart failure. These devices are replaced when pump complications arise if heart transplant is not possible. We present our experience with HeartMate II (HMII (Thoratec, Plesanton, California, United States)) LVAD pump exchange. Materials and Methods  We retrospectively reviewed all cases that required pump exchange due to LVAD complication from November 2011 until June 2016 at a single high-volume institution. The indications, demographics, and outcome were extracted and analyzed. Results  Of 250 total patients with implanted HMII LVADs, 16 (6%) required pump exchange during the study period. The initial indications for LVAD placement in these patients were bridge to transplantation ( n  = 6 [37.5%]) or destination therapy ( n  = 10 [62.5%]). Fifteen patients (93.8%) required pump exchange due to pump thrombosis and 1 (6.2%) due to refractory driveline infection. Nine patients (56.2%) underwent repeat median sternotomy while a left subcostal approach was used in the remaining seven patients. Fifteen patients (93.7%) survived until hospital discharge. During the follow-up period (median, 155 days), 11 patients remained alive and 4 of these underwent successful cardiac transplantation. Conclusion  HMII LVAD pump exchange can be safely performed for driveline infection or pump thrombosis when heart transplantation is not an option. Georg Thieme Verlag KG Stuttgart · New York.

  15. Regaining Candidacy for Heart Transplantation after Robotic Assisted Laparoscopic Radical Prostatectomy in Left Ventricular Assist Device Patient

    Directory of Open Access Journals (Sweden)

    Tariq A. Khemees

    2012-01-01

    Full Text Available Several factors may highlight the relevance of prostate cancer to the pre-heart-transplant population. First, the expansion in candidate selection criteria led to increased number of men over the age of fifty to be considered for heart transplantation. With the introduction of left ventricular assist device (LVAD therapy, waiting-list mortality has dramatically declined over the past decade. Additionally, transplant candidates are diligently screened for preexisting neoplasm while on the waiting list. Taken together, screening-detected prostate cancer may increasingly be diagnosed in patients on the waiting list. If discovered, it will pose unique challenge to clinicians as to date there has been no universally accepted management guideline. We report a case of LVAD-treated heart transplant candidate diagnosed with prostate cancer while on the waiting list. Patient screening demonstrated PSA elevation which prompted prostate biopsy. Low-risk clinically localized prostate cancer was confirmed and led to removal of patient from transplant list. When counseled regarding management of his cancer, the patient elected to undergo radical prostatectomy in a hope to regain candidacy for heart transplantation. Despite being of high surgical risk, multidisciplinary team approach led to successful management of prostate cancer and the patient eventually received heart transplant one year following prostatectomy.

  16. Recovery of major organ function in patients awaiting heart transplantation with Thoratec ventricular assist devices. Thoratec Ventricular Assist Device Principal Investigators.

    Science.gov (United States)

    Farrar, D J; Hill, J D

    1994-01-01

    The time course of recovery of hepatic and renal function was determined in 193 patients receiving Thoratec ventricular assist devices while awaiting transplantation at 41 hospitals in eight countries. The duration of circulatory support averaged 26 days (maximum 248 days) and the average ventricular assist device blood flow index was 2.7 +/- 0.5 L/min/m2 compared with a preoperative cardiac index of 1.4 +/- 0.7 L/min/m2. Renal and hepatic function improved in most patients in 1 to 3 weeks of support. When comparing patients with the longest durations on the ventricular assist device (60 to 248 days) to patients with the shortest durations (< 7 days), laboratory values were significantly improved: creatinine (-29%, from 1.7 +/- 1.2 to 1.2 +/- 0.5 mg/dl), blood urea nitrogen (-32%, from 37 +/- 27 to 25 +/- 14 mg/dl), serum glutamic-oxaloacetic transaminase (-81%, from 397 +/- 702 to 76 +/- 45 IU) and total bilirubin (-79%, from 7.0 +/- 8.6 to 1.5 +/- 0.7 mg/dl). However, the posttransplantation survival through hospital discharge was not significantly different: 88% (14 of 16) for patients supported for at least 60 days and 86% (43 of 50) for patients who underwent transplantation after only 1 week of support. Therefore renal and hepatic function improve during ventricular assist device support, but the survival rate after transplantation is not related to duration and is comparable to that of conventional heart transplantation for short or long periods of ventricular assist support. Although it is clearly important not to proceed to transplantation in patients with irreversible organ failure who have ventricular assist devices, these data suggest that as long as the patient is on the path to recovery, the outcome is basically the same as for patients who have full recovery of renal and hepatic function.

  17. Contemporary outcome of unplanned right ventricular assist device for severe right heart failure after continuous-flow left ventricular assist device insertion.

    Science.gov (United States)

    Yoshioka, Daisuke; Takayama, Hiroo; Garan, Reshad A; Topkara, Veli K; Han, Jiho; Kurlansky, Paul; Yuzefpolskaya, Melana; Colombo, Paolo C; Naka, Yoshifumi; Takeda, Koji

    2017-06-01

    The timely use of a right ventricular assist device (RVAD) becomes necessary for severe right heart failure (RHF) after left ventricular assist device (LVAD) insertion. This study evaluates outcomes in patients who required unplanned RVAD support early after continuous-flow (CF) LVAD insertion. We retrospectively reviewed 305 patients who underwent HeartMate II/HeartWare CF-LVAD insertion between 2009 and 2014. Twenty-seven (9%) patients required unplanned RVAD for severe RHF early after LVAD insertion. We compared early and late outcomes in patients with and without RVAD. The median time to RVAD implantation after primary CF-LVAD implantation was 1.0 (0-3) day. Seventeen (63%) patients could be weaned from RVAD after median of 14 (10-18) days. In 278 patients in the isolated LVAD group, overall survival at 3 and 12 months was 95% and 86%, whereas 59% and 54% in the unplanned RVAD group, respectively ( P  RHF at 1 year was 53% in the unplanned RVAD group and 90% in the isolated LVAD group ( P  = 0.002). Among patients who required unplanned RVAD after CF-LVAD implantation, above 60% of the patients could be weaned from RVAD. However, careful attention should be paid to the recurrent or sustained RHF.

  18. Organ Allocation In Adults With Congenital Heart Disease Listed For Heart Transplant: The Impact Of Ventricular Assist Devices

    Science.gov (United States)

    Gelow, Jill M.; Song, Howard K.; Weiss, Joseph B.; Mudd, James O.; Broberg, Craig S.

    2013-01-01

    Background Adults with congenital heart disease (CHD) listed for heart transplantation infrequently are supported with ventricular assist devices (VADs). This may disadvantage their priority for organ allocation. We sought to determine the relationship between VAD implantation and successful transplantation among patients listed for heart transplant. Methods Adults with CHD patients (N=1,250) were identified in the United Network for Organ Sharing (UNOS) database from 1985 – 2010 and compared to patients without congenital etiology for heart failure (N=59,606). VAD use at listing, listing status, status upgrades, and reasons for upgrade prior to transplant were trended at 5 year intervals and appropriate statistical comparisons were made between groups. Results Since 1985, VAD use prior to transplant has increased significantly in patients without CHD but not in CHD patients (17% vs. 3% in 2006–2010, p<0.0001). CHD patients were more likely to be listed as status 2, compared to those without (66% vs. 40%, p<0.001 for 2006–2010), and less likely to be upgraded to status 1 after listing (43% vs. 55%, p=0.03). Among those upgraded to status 1, CHD patients were less likely to have a VAD at transplant than those without (3% vs. 18%, p=0.005). VAD use was more likely to result in death in CHD patients. Conclusions VAD use is less common in CHD patients than patients without CHD, both at the time of listing and transplantation. Reduced VAD use appears to contribute to lower listing status and organ allocation. These differences have grown more disparate over time. Separate criteria for organ allocation for CHD patients may be justified. PMID:23921356

  19. Impact of Vice President Cheney on public interest in left ventricular assist devices and heart transplantation.

    Science.gov (United States)

    Pandey, Ambarish; Abdullah, Kazeen; Drazner, Mark H

    2014-05-01

    Although celebrity illnesses attract a significant amount of media attention in the United States, there are few studies that have looked at how celebrity health conditions impact the awareness of the illness in the general population. Recently, Vice President Cheney underwent left ventricular assist device (LVAD) implantation and subsequently a cardiac transplant. The aim of this study was to determine whether there was evidence of increased interest in these 2 procedures as assessed by social media. We determined the relative frequency of Google searches for LVAD and heart transplantation from 2004 to 2013 using Google trends. We also counted the number of YouTube videos and Twitter messages posted monthly concerning LVADs over a 7-year time frame. There was a significant spike in the Google search interest for LVAD and heart transplantation in the month when Vice President Cheney underwent the respective procedure. Similarly, there was a large increase in YouTube videos and Twitter messages concerning LVADs shortly after he was implanted. In total, these data support the concept that a public figure's illness can significantly influence the public's interest in that condition and its associated therapies. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Reversibility of Frailty After Bridge-to-Transplant Ventricular Assist Device Implantation or Heart Transplantation.

    Science.gov (United States)

    Jha, Sunita R; Hannu, Malin K; Newton, Phillip J; Wilhelm, Kay; Hayward, Christopher S; Jabbour, Andrew; Kotlyar, Eugene; Keogh, Anne; Dhital, Kumud; Granger, Emily; Connellan, Mark; Jansz, Paul; Spratt, Phillip M; Montgomery, Elyn; Smith, Angela; Harkess, Michelle; Tunicliff, Peta; Davidson, Patricia M; Macdonald, Peter S

    2017-07-01

    We recently reported that frailty is independently predictive of increased mortality in patients with advanced heart failure referred for heart transplantation (HTx). The aim of this study was to assess the impact of frailty on short-term outcomes after bridge-to-transplant ventricular assist device (BTT-VAD) implantation and/or HTx and to determine if frailty is reversible after these procedures. Between August 2013 and August 2016, 100 of 126 consecutive patients underwent frailty assessment using Fried's Frailty Phenotype before surgical intervention: 40 (21 nonfrail, 19 frail) BTT-VAD and 77 (60 nonfrail, 17 frail) HTx-including 17 of the 40 BTT-VAD supported patients. Postprocedural survival, intubation time, intensive care unit, and hospital length of stay were compared between frail and nonfrail groups. Twenty-six frail patients were reassessed at 2 months or longer postintervention. Frail patients had lower survival (63 ± 10% vs 94 ± 3% at 1 year, P = 0.012) and experienced significantly longer intensive care unit (11 vs 5 days, P = 0.002) and hospital (49 vs 25 days, P = 0.003) length of stay after surgical intervention compared with nonfrail patients. Twelve of 13 frail patients improved their frailty score after VAD (4.0 ± 0.8 to 1.4 ± 1.1, P < 0.001) and 12 of 13 frail patients improved their frailty score after HTx (3.2 ± 0.4 to 0.9 ± 0.9, P < 0.001). Handgrip strength and depression improved postintervention. Only a slight improvement in cognitive function was seen postintervention. Frail patients with advanced heart failure experience increased mortality and morbidity after surgical intervention with BTT-VAD or HTx. Among those who survive frailty is partly or completely reversible underscoring the importance of considering this factor as a dynamic not fixed entity.

  1. Frequency and Consequences of Right-Sided Heart Failure After Continuous-Flow Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Kurihara, Chitaru; Critsinelis, Andre C; Kawabori, Masashi; Sugiura, Tadahisa; Loor, Gabriel; Civitello, Andrew B; Morgan, Jeffrey A

    2018-02-01

    Postoperative right-sided heart failure (RHF) is a common complication after continuous-flow left ventricular assist device implantation. Studies have examined RHF in the perioperative period, but few have assessed late-onset RHF. We analyzed the incidence of early and late RHF in patients with HeartMate II and HeartWare left ventricular assist devices and associated morbidity, mortality, and independent predictors of RHF. We retrospectively analyzed records of 526 patients with chronic heart failure who underwent continuous-flow left ventricular assist device implantation; 147 (27.9%) developed RHF (early RHF, n = 87, 16.5%; late RHF, n = 74, 14.4%). We examined demographics, postoperative complications, and long-term survival rate. Patients with RHF or late RHF had higher mortality (p RHF. Patients with RHF had a higher incidence of acute kidney injury (20.4% vs 11.9%, p = 0.01). Device type did not affect the incidence of early, late, or overall RHF. Patients with severe RHF requiring right ventricular assist device support had a low success of bridge to transplantation (11.1% vs 33.3%, p = 0.02). In Cox regression models, RHF was an independent predictor of mortality (hazard ratio = 1.69, 95% confidence interval = 1.28 to 2.22, p RHF were identified. RHF was significantly associated with increased mortality and a higher incidence of postoperative acute kidney injury. RHF decreased the success rate of bridging patients to transplantation when a right ventricular assist device was required. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. HeartWare ventricular assist device as a bridge to heart transplantation in a patient with congenitally corrected transposition of the great arteries and dextrocardia.

    Science.gov (United States)

    Soofi, Muhammad A; Ignaszewski, Andrew P; Cheung, Anson W; Bashir, Jamil G

    2016-12-01

    Congenitally corrected transposition of the great arteries (ccTGA) is a rare condition with prevalence of Dextrocardia is reported among 20% of them. Among patients with ccTGA, heart failure is a common presentation, especially in the fourth or fifth decade of life and survival is dismal without heart transplantation. A left ventricular assist device (LVAD) is considered for bridge to transplantation if early heart transplantation is not available or as destination therapy for patients ineligible for heart transplant. Our patient had ccTGA and dextrocardia, after which he developed failure of a systemic ventricle and severe systemic atrioventricular valve, subpulmonic atrioventricular valve and aortic valve regurgitation along with paroxysmal atrial fibrillation. A third-generation ventricular assist device HeartWare ventricular assist device (HVAD, HeartWare, Inc., Framingham, MA, USA) was implanted as a bridge to transplantation with concomitant aortic valve replacement with a bioprosthetic valve. There is no prior publication on HVAD implantation in patient having both ccTGA and dextrocardia. Our case report includes the patient's summary and literature review encompassing limited experience of LVADs in patients with ccTGA and dextrocardia. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Comparison of total artificial heart and biventricular assist device support as bridge-to-transplantation.

    Science.gov (United States)

    Cheng, Allen; Trivedi, Jaimin R; Van Berkel, Victor H; Massey, H Todd; Slaughter, Mark S

    2016-10-01

    The use of left ventricular assist devices (LVAD) has increased significantly in the last decade. However, right heart dysfunction remains a problem despite the improved outcomes with continuous-flow LVADs. Surgical options for bridge to transplantation (BTT) in patients with biventricular failure are total artificial heart (TAH) or biventricular support (BiVAD). This study examines the differences in pre- and post-transplantation outcomes and survival in patients with TAH or BiVAD support as BTT. The United Network of Organ Sharing database was retrospectively queried from January 2005 to December 2014 to identify adult patients undergoing heart transplantation (n = 17,022). Patients supported with either TAH (n = 212) or BiVAD (n = 366) at the time of transplantation were evaluated. Pre- and post-transplantation Kaplan-Meier survival curves were examined. Cox regression model was used to study the hazard ratios of the association between TAH versus BiVAD support and post-transplant survival. The median age of the study groups was 49.8 ± 12.9 (TAH) and 47.2 ± 13.9 (BiVAD) years (range 18-74 years). There were more men, 87% versus 74%, in the TAH group (p < 0.0001) with greater body mass index, 27.3 ± 5.2 versus 25.6 ± 4.7 (p < 0.0001), compared to those with BiVADs. Creatinine was higher, 1.7 + 1.2 versus 1.3 + 0.8 mg/dL (p < 0.0001), in the TAH group before transplant. The 30-day, one-, and three-year post-transplantation survival was 88%, 78%, and 67%, respectively, for patients with TAH support versus 93%, 83%, and 73% (p = 0.06) for patients with BiVAD support. Cox regression model shows pre-transplant creatinine (HR = 1.21, p = 0.008) is associated with a lower post-transplant survival. TAH is not associated with a worse post-transplant survival (p = 0.1). There was no difference in wait-list survival in patients supported with TAH or BiVAD (p = 0.8). Although there has been a recent

  4. Right heart failure and "failure to thrive" after left ventricular assist device: clinical predictors and outcomes.

    Science.gov (United States)

    Baumwol, Jay; Macdonald, Peter S; Keogh, Anne M; Kotlyar, Eugene; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S

    2011-08-01

    This study determined predictors of early post-operative right heart failure (RHF) and its consequences, as well as predictors of those who clinically thrive longer term after insertion of a continuous-flow left ventricular assist device (LVAD). Pre-operative and latest follow-up data were analyzed for 40 consecutive patients who received third-generation centrifugal-flow LVADs. RHF was defined using previously described criteria, including post-operative inotropes, pulmonary vasodilator use, or right-sided mechanical support. Patients were also categorized according to clinical outcomes after LVAD insertion. LVADs were implanted as a bridge to transplantation (BTT) in 33 patients and as destination therapy in 7. Before LVAD implant, 22 patients were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level 1, and 17 were at level 2. Temporary mechanical assistance was present in 50% of the cohort at LVAD implantation. The 6-month survival/progression to transplant was 92.5%. Average LVAD support time was 385 days (range, 21-1,011 days). RHF developed postoperatively in 13 of 40 patients (32.5%). RHF patients had more severe pre-operative tricuspid incompetence than non-RHF patients. The BTT patients with evidence of RHF had poorer survival to transplant (6 of 11 [54.5%]) than those without RHF (20 of 22 [90.9%]), p = 0.027). There were no other hemodynamic or echocardiographic predictors of short-term RHF. After LVAD, 22 of the 40 patients (55%) thrived clinically. For BTT patients, 20 of 21 (95%) of those who thrived progressed to transplant or were alive at latest follow-up vs 6 of 12 (50%) of those who failed to thrive (FTT; p RHF. Age was the only significant predictor: the thrivers were significantly younger (43.7 ± 15.9 vs 60.3 ± 12.6 years; p RHF results in poorer survival/progression to transplantation for BTT patients and is predicted by greater pre-operative tricuspid incompetence. The most important predictor for those who

  5. Heart Rate and V˙O2 Concordance in Continuous-Flow Left Ventricular Assist Devices.

    Science.gov (United States)

    Kerrigan, Dennis J; Williams, Celeste T; Brawner, Clinton A; Ehrman, Jonathan K; Saval, Matthew A; Peterson, Edward L; Lanfear, David E; Tita, Christina; Velez, Mauricio; Selektor, Yelena; Keteyian, Steven J

    2016-03-01

    The American College of Sports Medicine currently recommends the HR reserve (HRR) method to guide exercise in individuals who have heart failure with reduced ejection fraction. This recommendation is based on the known association between %HRR and percentage of V˙O2 reserve (%V˙O2R) in this population. However, to our knowledge, no studies exist regarding this relation in individuals with a left ventricular assist device (LVAD). This article aimed to describe the relation between V˙O2 and surrogate markers of exercise intensity among patients with LVAD. Patients with continuous-flow LVAD (n = 24, seven females) completed a symptom-limited graded exercise test on a treadmill. HR and V˙O2 were measured continuously and averaged every 20 s. Regression equations were determined using a generalized estimating equation to predict %V˙O2R from %HRR, Borg RPE, and LVAD flow, overall and stratified by presence of pacing. Although the association between %HRR and %V˙O2R was good (R = 0.75), the slope and y-intercept for %HRR versus %V˙O2R was different from the line of identity (P = 0.002). However, when paced subjects were excluded (n = 8) from the analysis, there was no significant difference between the slope and y-intercept (= 0.036 + 0.937 × %HRR; SEE, 2%; P = 0.052). RPE showed a strong association with %V˙O2R (R = 0.84), whereas LVAD flow showed a weak (albeit statistically significant) association (R = 0.05). Both had slopes and y-intercepts that were different from the line of identity (P intensity.

  6. Ramp Study Hemodynamics, Functional Capacity, and Outcome in Heart Failure Patients with Continuous-Flow Left Ventricular Assist Devices

    DEFF Research Database (Denmark)

    Jung, Mette H; Gustafsson, Finn; Houston, Brian

    2016-01-01

    Ramp studies-measuring changes in cardiac parameters as a function of serial pump speed changes (revolutions per minute [rpm])-are increasingly used to evaluate function and malfunction of continuous-flow left ventricular assist devices (CF-LVADs). We hypothesized that ramp studies can predict...... patients (HeartMate II, Thoratec Corporation, Pleasanton, CA). Functional status was evaluated in 70% (31/44); average 6 minute walk test (6MWT) was 312 ± 220 min, New York Heart Association (NYHA) I-II/III-IV (70/30%) and activity scores very low-low/moderate-very high (55/45%). Decrease in pulmonary...

  7. Performance and management of implantable lithium battery systems for left ventricular assist devices and total artificial hearts

    Science.gov (United States)

    Dodd, J.; Kishiyama, C.; Mukainakano, Hiroshi; Nagata, M.; Tsukamoto, H.

    A lithium ion cell designed for implantable medical devices was tested for its performance as a power source for left ventricular assist devices (LVAD) or total artificial hearts (TAH). These two cardiovascular devices require high power, and thus a high current (0.5-3 A) and high voltage (20-30 V). Since these are implantable medical devices, in addition to high power capability, the power source should have long cycle life and calendar life, as well as high safety. The QL0700I, a 700 mAh cell, was cycled at 0.5 C rate as well as at 1.5 C rate, and the cycle life capacity retention was evaluated after numerous cycles. A battery pack consisting of seven QL0700I cells in series, with a battery management system (BMS) connected, was tested for rate capability as well as safety protection.

  8. High fidelity computational simulation of thrombus formation in Thoratec HeartMate II continuous flow ventricular assist device.

    Science.gov (United States)

    Wu, Wei-Tao; Yang, Fang; Wu, Jingchun; Aubry, Nadine; Massoudi, Mehrdad; Antaki, James F

    2016-12-01

    Continuous flow ventricular assist devices (cfVADs) provide a life-saving therapy for severe heart failure. However, in recent years, the incidence of device-related thrombosis (resulting in stroke, device-exchange surgery or premature death) has been increasing dramatically, which has alarmed both the medical community and the FDA. The objective of this study was to gain improved understanding of the initiation and progression of thrombosis in one of the most commonly used cfVADs, the Thoratec HeartMate II. A computational fluid dynamics simulation (CFD) was performed using our recently updated mathematical model of thrombosis. The patterns of deposition predicted by simulation agreed well with clinical observations. Furthermore, thrombus accumulation was found to increase with decreased flow rate, and can be completely suppressed by the application of anticoagulants and/or improvement of surface chemistry. To our knowledge, this is the first simulation to explicitly model the processes of platelet deposition and thrombus growth in a continuous flow blood pump and thereby replicate patterns of deposition observed clinically. The use of this simulation tool over a range of hemodynamic, hematological, and anticoagulation conditions could assist physicians to personalize clinical management to mitigate the risk of thrombosis. It may also contribute to the design of future VADs that are less thrombogenic.

  9. Repair of pectus excavatum during HeartMate II left ventricular assist device placement.

    Science.gov (United States)

    Tchantchaleishvili, Vakhtang; Massey, Howard Todd

    2016-01-01

    Pectus excavatum deformity often remains clinically asymptomatic even in cases of a severely diminished thoracic volume and frequently remains uncorrected. In the patient population that requires left ventricular assist device (LVAD) placement, a diminished thoracic volume can be problematic and lead to significant challenges in pump and outflow cannula positioning. Here we present a case of pectus excavatum correction during LVAD placement to show that this deformity can be successfully addressed with minimal, if any, additional operative risk at the time of LVAD implant. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  10. Constrictive Pericarditis in the Presence of Remaining Remnants of a Left Ventricular Assist Device in a Heart Transplanted Patient

    Directory of Open Access Journals (Sweden)

    R. Rivinius

    2015-01-01

    Full Text Available Constrictive pericarditis (CP is a severe subform of pericarditis with various causes and clinical findings. Here, we present the unique case of CP in the presence of remaining remnants of a left ventricular assist device (LVAD in a heart transplanted patient. A 63-year-old man presented at the Heidelberg Heart Center outpatient clinic with progressive dyspnea, fatigue, and loss of physical capacity. Heart transplantation (HTX was performed at another heart center four years ago and postoperative clinical course was unremarkable so far. Pharmacological cardiac magnetic resonance imaging (MRI stress test was performed to exclude coronary ischemia. The test was negative but, accidentally, a foreign body located in the epicardial adipose tissue was found. The foreign body was identified as the inflow pump connection of an LVAD which was left behind after HTX. Echocardiography and cardiac catheterization confirmed the diagnosis of CP. Surgical removal was performed and the epicardial tubular structure with a diameter of 30 mm was carefully removed accompanied by pericardiectomy. No postoperative complications occurred and the patient recovered uneventfully with a rapid improvement of symptoms. On follow-up 3 and 6 months later, the patient reported about a stable clinical course with improved physical capacity and absence of dyspnea.

  11. Clinical Experience With Sternotomy Versus Subcostal Approach for Exchange of HeartMate II Left Ventricular Assist Device.

    Science.gov (United States)

    Soleimani, Behzad; Stephenson, Edward R; Price, Lauren C; El-Banayosy, Aly; Pae, Walter E

    2015-11-01

    The safety and efficacy of exchanging the HeartMate II (Thoratec Corp, Pleasanton, CA) left ventricular assist device (LVAD) through a less invasive subcostal approach remains unclear. We reviewed the records of 17 patients who underwent exchange of their HeartMate II device at our institution since 2007. We divided the cohort into devices exchanged through a subcostal (SC) approach versus a median sternotomy (MS) approach and obtained data pertaining to the short- and long-term outcomes. Nine patients had pump exchange through an MS approach versus 8 patients who underwent an SC approach. The mean duration of support with the first pump was 540 ± 450 days. The reason for exchange was electromechanical failure (7 patients), thrombosis (8 patients), and infection (2 patients). There were no 30-day perioperative deaths with either approach. Compared with sternotomy, patients who underwent an SC approach had significantly shorter operative times (131 vs 222 minutes; p = 0.001) and lower reoperation rates for bleeding (0 vs 44.4%; P = 0.05) and required fewer transfused blood products (packed red cells, 3.5 units vs 7.1 units; p approach had shorter postoperative stays in the intensive care unit (ICU) (5 days vs 13.8 days; p approach. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Risk assessment and comparative effectiveness of left ventricular assist device and medical management in ambulatory heart failure patients: design and rationale of the ROADMAP clinical trial.

    Science.gov (United States)

    Rogers, Joseph G; Boyle, Andrew J; O'Connell, John B; Horstmanshof, Douglas A; Haas, Donald C; Slaughter, Mark S; Park, Soon J; Farrar, David J; Starling, Randall C

    2015-02-01

    Mechanical circulatory support is now a proven therapy for the treatment of patients with advanced heart failure and cardiogenic shock. The role for this therapy in patients with less severe heart failure is unknown. The objective of this study is to examine the impact of mechanically assisted circulation using the HeartMate II left ventricular assist device in patients who meet current US Food and Drug Administration-defined criteria for treatment but are not yet receiving intravenous inotropic therapy. This is a prospective, nonrandomized clinical trial of 200 patients treated with either optimal medical management or a mechanical circulatory support device. This trial will be the first prospective clinical evaluation comparing outcomes of patients with advanced ambulatory heart failure treated with either ongoing medical therapy or a left ventricular assist device. It is anticipated to provide novel insights regarding relative outcomes with each treatment and an understanding of patient and provider acceptance of the ventricular assist device therapy. This trial will also provide information regarding the risk of events in "stable" patients with advanced heart failure and guidance for the optimal timing of left ventricular assist device therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Preload Sensitivity in Cardiac Assist Devices

    Science.gov (United States)

    Fukamachi, Kiyotaka; Shiose, Akira; Massiello, Alex; Horvath, David J.; Golding, Leonard A. R.; Lee, Sangjin; Starling, Randall C.

    2013-01-01

    With implantable cardiac assist devices increasingly proving their effectiveness as therapeutic options for end-stage heart failure, it is important for clinicians to understand the unique physiology of device-assisted circulation. Preload sensitivity as it relates to cardiac assist devices is derived from the Frank-Starling relationship between human ventricular filling pressures and ventricular stroke volume. In this review, we stratify the preload sensitivity of 17 implantable cardiac assist devices relative to the native heart and discuss the effect of preload sensitivity on left ventricular volume unloading, levels of cardiac support, and the future development of continuous-flow total artificial heart technology. PMID:23272869

  14. Emergency HeartWare Ventricular Assist Device (HVAD) exchange due to pump thrombosis using minimally invasive technique.

    Science.gov (United States)

    Antończyk, Remigiusz; Trejnowska, Ewa; Pacholewicz, Jerzy; Wolny, Tomasz; Nadziakiewicz, Paweł; Antończyk, Karolina; Copik, Izabela; Piontek, Magdalena; Jasińska, Małgorzata; Filipiak, Krzysztof; Głowacki, Maciej; Gawlikowski, Maciej; Borowicz, Marcin; Kustosz, Roman; Waszak, Jacek; Przybyłowski, Piotr; Zembala, Marian; Zakliczyński, Michał; Zembala, Michał Oskar

    2017-03-01

    Left ventricular assist device (LVAD) thrombosis remains a dreadful complication of mechanical circulatory support, with an incidence of 8-12% depending on the pump type and patient's comorbidities. Fibrinolysis may be considered early in pump thrombosis, but when contraindicated a pump exchange remains the only alternative. This short report documents an emergency LVAD exchange in a 55-year-old man who underwent LVAD (HeartWare Inc) implantation in 2013 as a bridge to transplantation. Four months after the initial surgery, he suffered from a hemorrhagic stroke despite properly managed anticoagulation. On February 17th, 2017 he was re-admitted with LVAD pump thrombosis. As fibrinolysis was contraindicated, an emergency pump exchange was performed via a limited thoracic incision in order to minimize surgical trauma, reduce intraoperative complications and facilitate immediate post-operative recovery. This report documents the very first LVAD pump exchange as well as the first one performed via a minimally invasive approach in Poland.

  15. Incidence and clinical significance of late right heart failure during continuous-flow left ventricular assist device support.

    Science.gov (United States)

    Takeda, Koji; Takayama, Hiroo; Colombo, Paolo C; Yuzefpolskaya, Melana; Fukuhara, Shinichi; Han, Jiho; Kurlansky, Paul; Mancini, Donna M; Naka, Yoshifumi

    2015-08-01

    Right heart failure (RHF) is an unresolved issue during continuous-flow left ventricular assist device (LVAD) support. Little is known about the incidence and clinical significance of late RHF during LVAD support. Between May 2004 and December 2013, 336 patients underwent continuous-flow LVAD implantation. Of these, 293 patients (87%) discharged with isolated LVAD support were included in this study. Late RHF was defined as HF requiring re-admission and medical or surgical intervention after initial surgery. Late RHF occurred in 33 patients (11%) at a median of 99 days after discharge (range 19 to 1,357 days). Freedom from late RHF rates were 87%, 84% and 79% at 1, 2 and 3 years, respectively. RHF recurred in 15 patients. Three patients required right ventricular assist device insertion. Univariable Cox proportional hazards regression model showed diabetes mellitus (HR 2.05, 95% CI 1.03 to 4.06, p = 0.04), body mass index >29 (HR 2.47, 95% CI 1.24 to 4.94, p = 0.01) and blood urea nitrogen level >41 mg/dl (HR 2.19; 95% CI 1.10 to 4.36; p = 0.025) as significant predictors for late RHF. Estimated on-device survival rates at 2 years were 73% in the RHF group and 82% in the non-RHF group (p = 0.20). However, overall survival at 2 years was significantly worse in patients who developed late RHF (60% vs 85%, p = 0.016). This reduction was mostly attributed to worse overall outcomes in the bridge-to-transplant (BTT) population. Late RHF is common after continuous-flow LVAD implantation, but does not affect survival during LVAD support. However, it is associated with worse overall outcomes in the BTT population. Published by Elsevier Inc.

  16. Macrovascular and microvascular function after implantation of left ventricular assist devices in end-stage heart failure: Role of microparticles.

    Science.gov (United States)

    Sansone, Roberto; Stanske, Beate; Keymel, Stefanie; Schuler, Dominik; Horn, Patrick; Saeed, Diyar; Boeken, Udo; Westenfeld, Ralf; Lichtenberg, Artur; Kelm, Malte; Heiss, Christian

    2015-07-01

    The hemodynamic vascular consequences of implanting left ventricular assist devices (LVADs) have not been studied in detail. We investigated the effect of LVAD implantation compared with heart transplant (HTx) on microvascular and macrovascular function in patients with end-stage heart failure and evaluated whether microparticles may play a role in LVAD-related endothelial dysfunction. Vascular function was assessed in patients with end-stage heart failure awaiting HTx, patients who had undergone implantation of a continuous-flow centrifugal LVAD, and patients who had already received a HTx. Macrovascular function was measured by flow-mediated vasodilation (FMD) using high-resolution ultrasound of the brachial artery. Microvascular function was assessed in the forearm during reactive hyperemia using laser Doppler perfusion imaging and pulsed wave Doppler. Age-matched patients without heart failure and without coronary artery disease (CAD) (healthy control subjects) and patients with stable CAD served as control subjects. Circulating red blood cell (CD253(+)), leukocyte (CD45(+)), platelet (CD31(+)/CD41(+)), and endothelial cell (CD31(+)/CD41(-), CD62e(+), CD144(+)) microparticles were determined by flow cytometry and free hemoglobin by enzyme-linked immunosorbent assay. FMD and microvascular function were significantly impaired in patients with end-stage heart failure compared with healthy control subjects and patients with stable CAD. LVAD implantation led to recovery of microvascular function, but not FMD. In parallel, increased free hemoglobin was observed along with red and white cell microparticles and endothelial and platelet microparticles. This finding indicates destruction of blood cells with release of hemoglobin and activation of endothelial cells. HTx and LVAD implantation led to similar improvements in microvascular function. FMD increased and microparticle levels decreased in patients with HTx, whereas shear stress during reactive hyperemia was

  17. Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

    Directory of Open Access Journals (Sweden)

    Khayat Andre

    2011-01-01

    Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

  18. Catheter ablation of atrial flutter in patients with left ventricular assist device improves symptoms of right heart failure.

    Science.gov (United States)

    Hottigoudar, Rashmi U; Deam, Allen G; Birks, Emma J; McCants, Kelly C; Slaughter, Mark S; Gopinathannair, Rakesh

    2013-01-01

    Persistent atrial flutter (AFL) in left ventricular assist device (LVAD) recipients can result in loss of AV synchrony, impaired ventricular filling and right heart failure (RHF). The authors report the largest series of HeartMate II (HMII) patients who developed AFL with decompensated RHF, which successfully resolved with AFL ablation. Eight patients with HMII LVAD (mean age, 57±12 years) had medically refractory AFL, with 7 developing de novo AFL after LVAD implant (onset range, 2 days-22 months post-implant). Three patients developed recurrent syncope, 2 had inappropriate implantable cardioverter-defibrillator shocks, and 6 had new or escalating need for inotropes. All had features of decompensated RHF. Seven patients underwent electrophysiology testing where mapping confirmed typical counterclockwise AFL (mean AFL cycle length, 252±49 ms) and radiofrequency ablation of cavotricuspid isthmus restored sinus rhythm in all patients. Complete resolution of symptoms and signs of RHF with improved quality of life were noted in all. No procedural complications were noted. During a mean follow-up of 9±5 months, all patients remained free of atrial flutter. Catheter ablation of AFL in LVAD patients is safe and highly effective, resulting in immediate and significant improvement in symptoms of RHF, and should be considered first-line therapy for AFL in these patients. © 2013 Wiley Periodicals, Inc.

  19. Impact of chlorhexidine gluconate intolerance on driveline infection during chronic HeartMate II left ventricular assist device support.

    Science.gov (United States)

    Son, Andre Y; Stein, Louis H; DeAnda, Abe; Katz, Stuart D; Smith, Deane E; Reyentovich, Alex; Balsam, Leora B

    2017-01-13

    Driveline exit site (DLES) management following left ventricular assist device implantation is important for preventing driveline infection (DLI). While chlorhexidine gluconate (CHG) is generally recommended for DLES antisepsis, CHG intolerance can develop, resulting in a need for alternative antiseptics. We reviewed our institutional experience with DLES antisepsis methods in HeartMate II patients, comparing outcomes of patients with and without CHG intolerance. Between October 2011 and March 2016, 44 patients underwent primary HeartMate II implantation. CHG was used for DLES antisepsis and povidone-iodine (PVP-I) was used in patients with CHG intolerance. DLI was defined by Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria. Of 44 patients, 37 (84%) received CHG and 7 (16%) received PVP-I antisepsis due to CHG intolerance. Five patients (11.4%) developed a DLI, with an event per patient-year rate of 0.07. Median length of support was 521 days (interquartile range 202-881 days). Characteristics were similar between patients with and without DLI. However, a larger proportion of patients with DLI had CHG intolerance compared to patients without DLI (60.0% vs. 10.3%, p:0.05). Causative organisms were Staphylococcus aureus in CHG-intolerant patients and Stenotrophomonas and Acinetobacter in CHG-tolerant patients. Kaplan-Meier method and log-rank test demonstrated decreased infection-free days in patients using PVP-I rather than CHG (p:0.01). While the etiology of DLI is multifactorial, CHG intolerance appears to be a risk factor. Our findings highlight the need for larger studies comparing the efficacy of antiseptics for DLES care, particularly for patients with CHG contraindications.

  20. Exercise blood pressure response during assisted circulatory support: comparison of the total artificial [corrected] heart with a left ventricular assist device during rehabilitation.

    Science.gov (United States)

    Kohli, Harajeshwar S; Canada, Justin; Arena, Ross; Tang, Daniel G; Peberdy, Mary Ann; Harton, Suzanne; Flattery, Maureen; Doolin, Kelly; Katlaps, Gundars J; Hess, Michael L; Kasirajan, Vigneshwar; Shah, Keyur B

    2011-11-01

    The total artificial heart (TAH) consists of two implantable pneumatic pumps that replace the heart and operate at a fixed ejection rate and ejection pressure. We evaluated the blood pressure (BP) response to exercise and exercise performance in patients with a TAH compared to those with a with a continuous-flow left ventricular assist device (LVAD). We conducted a single-center, retrospective study of 37 patients who received a TAH and 12 patients implanted with an LVAD. We measured the BP response during exercise, exercise duration and change in tolerated exercise workload over an 8-week period. In patients with a TAH, baseline BP was 120/69 ± 13/13, exercise BP was 118/72 ± 15/10 and post-exercise BP was 120/72 ± 14/12. Mean arterial BP did not change with exercise in patients with a TAH (88 ± 10 vs 88 ± 11; p = 0.8), but increased in those with an LVAD (87 ± 8 vs 95 ± 13; p Heart and Lung Transplantation. All rights reserved.

  1. Comparative analysis of von Willebrand factor profiles after implantation of left ventricular assist device and total artificial heart.

    Science.gov (United States)

    Reich, H J; Morgan, J; Arabia, F; Czer, L; Moriguchi, J; Ramzy, D; Esmailian, F; Lam, L; Dunhill, J; Volod, O

    2017-08-01

    Essentials Bleeding is a major source of morbidity during mechanical circulatory support. von Willebrand factor (VWF) multimer loss may contribute to bleeding. Different patterns of VWF multimer loss were seen with the two device types. This is the first report of total artificial heart associated VWF multimer loss. Background Bleeding remains a challenge during mechanical circulatory support and underlying mechanisms are incompletely understood. Functional von Willebrand factor (VWF) impairment because of loss of high-molecular-weight multimers (MWMs) produces acquired von Willebrand disease (VWD) after left ventricular assist device (LVAD). Little is known about VWF multimers with total artificial hearts (TAHs). Here, VWF profiles with LVADs and TAHs are compared using a VWD panel. Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis. Results Twelve patients with LVADs and 12 with TAHs underwent VWD evaluation. All had either normal (47.8%) or elevated (52.2%) VWF:RCo, normal (26.1%) or elevated (73.9%) VWF:Ag and 50.0% were disproportional (ratio ≤ 0.7). Multimeric analysis showed abnormal patterns in all patients with LVADs: seven with high MWM loss; five with highest MWM loss. With TAH, 10/12 patients had abnormal patterns: all with highest MWM loss. High MWM loss correlated with presence of LVAD and highest MWM loss with TAH. Increased low MWMs were detected in 22/24. Conclusion Using VWF multimeric analysis, abnormalities after LVAD or TAH were detected that would be missed with measurements of VWF level alone: loss of high MWM predominantly in LVAD, loss of highest MWM in TAH, and elevated levels of low MWM in both. This is the first study to describe TAH-associated highest MWM loss, which may contribute to bleeding. © 2017 International Society on Thrombosis and

  2. Economic Evaluation of Left Ventricular Assist Devices for Patients With End Stage Heart Failure Who Are Ineligible for Cardiac Transplantation.

    Science.gov (United States)

    Chew, Derek S; Manns, Braden; Miller, Robert J H; Sharma, Nakul; Exner, Derek V

    2017-10-01

    Continuous flow (CF) left ventricular assist devices (LVADs) improve survival in end-stage heart failure patients who are ineligible for cardiac transplantation. Their use in this population (referred to as destination therapy) is increasing in many countries, yet they are not routinely funded for this indication in Canada. We assessed the cost-effectiveness of destination therapy CF-LVADs from the perspective of the Canadian health care payer. A Markov model was used to project the outcomes and costs of 2 treatment pathways, CF-LVAD implantation and medical management alone, in an end-stage heart failure patient cohort ineligible for transplantation. Clinical and cost input estimates were informed from the available literature. Model outcomes included costs (in 2015 Canadian dollars), quality-adjusted life-years (QALYs), and the cost per QALY gained. Compared with medical management, CF-LVAD patients had higher costs ($284,287 vs $31,984) and QALYs (1.48 vs 0.39) over a lifetime horizon. The incremental cost per QALY gained was $230,692. The model was most sensitive to device implantation costs, and the clinical effectiveness of CF-LVADs on survival and quality of life. A scenario analysis using contemporary survival data resulted in a cost per QALY gained of $125,936. When applying contemporary LVAD survival trends, the model showed that the cost of initial LVAD implantation needed to be less than $123,000 to be considered cost-effective. The incremental cost per QALY for destination therapy CF-LVADs is predicted to be above usual thresholds for funding in Canada. In some plausible scenarios, its cost-effectiveness is similar to dialysis for kidney failure, a therapy that is also immediately life-saving. Because of this, there will be likely ongoing pressure to fund CF-LVADs for a subset of patients ineligible for transplantation. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  3. Normalisation of haemodynamics in patients with end-stage heart failure with continuous-flow left ventricular assist device therapy.

    Science.gov (United States)

    Gupta, Sunil; Woldendorp, Kei; Muthiah, Kavitha; Robson, Desiree; Prichard, Roslyn; Macdonald, Peter S; Keogh, Anne M; Kotlyar, Eugene; Jabbour, Andrew; Dhital, Kumud; Granger, Emily; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S

    2014-10-01

    New generation continuous-flow left ventricular assist devices (LVADs) utilise centrifugal pumps. Data concerning their effect on patient haemodynamics, ventricular function and tissue perfusion is limited. We aimed to document these parameters following HeartWare centrifugal continuous-flow LVAD (HVAD) implantation and to assess the impact of post-operative right heart failure (RHF). We reviewed 53 consecutive patients (mean age 49.5 ± 14.1 yrs) with HVAD implanted in the left ventricle, at St. Vincent's Hospital, Sydney, between January 2007 and August 2012. Available paired right heart catheterisation (n=35) and echocardiography (n=39) data was reviewed to assess response of invasive haemodynamics and ventricular function to LVAD support. A total of 28 patients (53%) were implanted from interim mechanical circulatory support. Seventeen patients (32%) required short-term post-implant veno-pulmonary artery extracorporeal membrane oxygenation. At 100 ± 61 days post-implant, mean pulmonary artery pressure and mean pulmonary capillary wedge pressure decreased from 38.8 ± 7.7 to 22.9 ± 7.7 mmHg and 28.3 ± 6.4 to 13.4 ± 5.4 mmHg respectively (pRHF patients (72.2%, n=18) compared to those without (96.9%, n=35, p=0.01). HVAD support improves haemodynamics, LV dimensions and renal function. Following implantation with a centrifugal continuous-flow LVAD, RHF remains a significant risk with a tendency to worse outcomes in the short to medium term. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  4. Can a Left Ventricular Assist Device in Individuals with Advanced Systolic Heart Failure Improve or Reverse Frailty?

    Science.gov (United States)

    Maurer, Mathew S; Horn, Evelyn; Reyentovich, Alex; Dickson, Victoria Vaughan; Pinney, Sean; Goldwater, Deena; Goldstein, Nathan E; Jimenez, Omar; Teruya, Sergio; Goldsmith, Jeff; Helmke, Stephen; Yuzefpolskaya, Melana; Reeves, Gordon R

    2017-11-01

    Frailty, characterized by low physiological reserves, is strongly associated with vulnerability to adverse outcomes. Features of frailty overlap with those of advanced heart failure, making a distinction between them difficult. We sought to determine whether implantation of a left ventricular assist device (LVAD) would decrease frailty. Prospective, cohort study. Five academic medical centers. Frail individuals (N = 29; mean age 70.6 ± 5.5, 72.4% male). Frailty, defined as having 3 or more of the Fried frailty criteria, was assessed before LVAD implantation and 1, 3, and 6 months after implantation. Other domains assessed included quality of life, using the Kansas City Cardiomyopathy Questionnaire; mood, using the Patient Health Questionnaire; and cognitive function, using the Trail-Making Test Part B. After 6 months, three subjects had died, and one had undergone a heart transplant; of 19 subjects with serial frailty measures, the average number of frailty criteria decreased from 3.9 ± 0.9 at baseline to 2.8 ± 1.4 at 6 months (P = .003). Improvements were observed after 3 to 6 months of LVAD support, although 10 (52.6%) participants still had 3 or more Fried criteria, and all subjects had at least one at 6 months. Changes in frailty were associated with improvement in QOL but not with changes in mood or cognition. Higher estimated glomerular filtration rate at baseline was independently associated with a decrease in frailty. Frailty decreased in approximately half of older adults with advanced heart failure after 6 months of LVAD support. Strategies to enhance frailty reversal in this population are worthy of additional study. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  5. Reversibility of Frailty After Bridge-to-Transplant Ventricular Assist Device Implantation or Heart Transplantation

    Directory of Open Access Journals (Sweden)

    Sunita R. Jha, BMed Sci (Hons

    2017-07-01

    Conclusions. Frail patients with advanced heart failure experience increased mortality and morbidity after surgical intervention with BTT-VAD or HTx. Among those who survive frailty is partly or completely reversible underscoring the importance of considering this factor as a dynamic not fixed entity.

  6. Bridge to transplantation using paracorporeal biventricular assist devices or the syncardia temporary total artificial heart: is there a difference?

    Science.gov (United States)

    Nguyen, A; Pozzi, M; Mastroianni, C; Léger, P; Loisance, D; Pavie, A; Leprince, P; Kirsch, M

    2015-06-01

    Biventricular support can be achieved using paracorporeal ventricular assist devices (p-BiVAD) or the Syncardia temporary total artificial heart (t-TAH). The purpose of the present study was to compare survival and morbidity between these devices. Data from 2 French neighboring hospitals were reviewed. Between 1996 and 2009, 148 patients (67 p-BiVADs and 81 t-TAH) underwent primary, planned biventricular support. There were 128 (86%) males aged 44±13 years. Preoperatively, p-BiVAD recipients had significantly lower systolic and diastolic blood pressures, more severe hepatic cytolysis and higher white blood cell counts than t-TAH recipients. In contrast, t-TAH patients had significantly higher rates of pre-implant ECLS and hemofiltration. Mean support duration was 79±100 days for the p-BiVAD group and 71±92 for t-TAH group (P=0.6). Forty two (63%) p-BiVAD recipients were bridged to transplantation (39, 58%) or recovery (3, 5%), whereas 51 (63%) patients underwent transplantation in the t-TAH group. Death on support was similar between groups (p-BiVAD, 26 (39%); t-TAH, 30 (37%); P=0.87). Survival while on device was not significantly different between patient groups and multivariate analysis showed that only preimplant diastolic blood pressure and alanine amino-transferase levels were significant predictors of death. Post-transplant survival in the p-BiVAD group was 76±7%, 70±8%, and 58±9% at 1, 3, and 5 years after transplantation, respectively, and was similar to that of the t-TAH group (77±6%, 72±6%, and 70±7%, P=0.60). Survival while on support and up to 5 years after heart transplantation was not significantly different in patients supported by p-BiVADs or t-TAH. Multivariate analysis revealed that survival while on transplantation was not affected by the type of device implanted.

  7. The increasing importance of percutaneous mechanical circulatory assist device therapy in heart failure management

    Directory of Open Access Journals (Sweden)

    Ricardo A Weis

    2015-01-01

    Full Text Available Introduction: Advances in medical and surgical care have made it possible for an increasing number of patients with Congenital Heart disease (CHD to live into adulthood. Transposition of the great vessels (TGV is the most common cyanotic congenital cardiac disease where the right ventricle serves as systemic ventricle. It is not uncommon for these patients to have systemic ventricular failure requiring transplantation. Study Design: Hemodynamic decompensation in these patients can be swift and difficult to manage. Increasingly percutaneous LVAD′s such as the Impella (Abiomed, Mass, USA are gaining popularity in these situations owing to their relative ease of placement, both in and outside of the operating room. Conclusion: In this paper we demonstrate that Impella (IMP CP placement through the axillary artery approach shows to be suitable option for short term cardiac support and improvement of end organ perfusion in anticipation of cardiac transplantation.

  8. The increasing importance of percutaneous mechanical circulatory assist device therapy in heart failure management.

    Science.gov (United States)

    Weis, Ricardo A; Devaleria, Patrick A; Koushik, Sarang; Ramakrishna, Harish

    2015-01-01

    Advances in medical and surgical care have made it possible for an increasing number of patients with Congenital Heart disease (CHD) to live into adulthood. Transposition of the great vessels (TGV) is the most common cyanotic congenital cardiac disease where the right ventricle serves as systemic ventricle. It is not uncommon for these patients to have systemic ventricular failure requiring transplantation. Hemodynamic decompensation in these patients can be swift and difficult to manage. Increasingly percutaneous LVAD's such as the Impella (Abiomed, Mass, USA) are gaining popularity in these situations owing to their relative ease of placement, both in and outside of the operating room. In this paper we demonstrate that Impella (IMP) CP placement through the axillary artery approach shows to be suitable option for short term cardiac support and improvement of end organ perfusion in anticipation of cardiac transplantation.

  9. Telemonitoring and Medical Care of Heart Failure Patients Supported by Left Ventricular Assist Devices - The Medolution Project.

    Science.gov (United States)

    Reiss, Nils; Schmidt, Thomas; Müller-von Aschwege, Frerk; Thronicke, Wolfgang; Hoffmann, Jan-Dirk; Röbesaat, Jenny Inge; Deniz, Ezin; Hein, Andreas; Krumm, Heiko; Stewing, Franz-Josef; Willemsen, Detlev; Schmitto, Jan Dieter; Feldmann, Christina

    2017-01-01

    Long-term survival after left ventricular assist device (LVAD) implantation in heart failure patients is mainly determined by a sophisticated after-care. Ambulatory visits only take place every 12 weeks. In case of life-threatening complications (pump thrombosis, driveline infection) this might lead to delayed diagnosis and delayed intervention. It is the intention of the international project Medolution (Medical care evolution) to develop new approaches in order to create best structures for telemonitoring of LVAD patients. In the very early period of the project a questionnaire was sent to 180 LVAD patients to evaluate the need and acceptance of telemonitoring. Thereafter, a graphical user interface (GUI) mockup was developed as one of the first steps to improve the continuous contact between the LVAD patient and the physician. As a final goal the Medolution project aims to bundle all relevant informations from different data sources into one platform in order to provide the physician a comprehensive overview of a patient's situation. In the systems background a big data analysis should run permanently and should try to detect abnormalities and correlations as well. At crucial events, a notification system should inform the physician and should provide the causing data via a decision support system. With this new system we are expecting early detection and prevention of common and partially life-threatening complications, less readmissions to the hospital, an increase in quality of life for the patients and less costs for the health care system as well.

  10. Experimental study on the Reynolds and viscous shear stress of bileaflet mechanical heart valves in a pneumatic ventricular assist device.

    Science.gov (United States)

    Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2009-01-01

    Our group is currently developing a pneumatic ventricular assist device (PVAD). In general, the major causes of hemolysis in a pulsatile VAD are cavitation, and Reynolds shear stress (RSS) in the mechanical heart valve (MHV). In a previous study, we investigated MHV cavitation. To select the optimal bileaflet valve for our PVAD, in the current study, we investigated RSS and viscous shear stress (VSS) downstream of three different types of commercial bileaflet valves by means of 2D particle image velocimetry (PIV). To carry out flow visualization inside the blood pump and near the valve, we designed a model pump with the same configuration as that of our PVAD. Three types of bileaflet valves (i.e., the ATS valve, the St. Jude valve, and the Sorin Bicarbon valve) were mounted at the aortic position of the model pump, and flow was visualized according to the PIV method. The maximum flow velocity and RSS of the Sorin Bicarbon valve were lower than those of the other two bileaflet valves. The maximum VSS was only 1% of the maximum RSS. Thus, the effect of VSS on blood cell trauma was neglected. The Sorin Bicarbon valve exhibited relatively low levels of RSS, and was therefore considered to be the best valve for our PVAD among the three valves tested.

  11. Left ventricular assist device as 'bridge to weight loss' prior to transplantation in obese patients with advanced heart failure.

    Science.gov (United States)

    Dhesi, Pavittarpaul; Simsir, Sinan A; Daneshvar, Daniel; Rafique, Asim; Phan, Anita; Schwarz, Ernst R

    2011-01-01

    Obesity is a risk factor for heart failure (HF) and associated with poor outcomes after cardiac transplantation. We assessed change in total body weight, morbidity and mortality in obese heart failure patients after implantation of a left ventricular assist device (LVAD) compared to medical management. Nineteen patients (9 females, age 51.3 ± 10 years) with a body mass index (BMI) ≥ 30.0 kg/m² and advanced HF (NYHA class III-IV, stage D) were evaluated. Thirteen (group 1) received insertion of a LVAD as bridge to transplantation. The remaining patients (group 2) were medically managed. All were advised on lifestyle modification. At baseline, group 1 (49.1 ± 10.7 years) had a total body weight (BW) of 246.6 ± 34.9 pounds (mean ± SD) and a BMI of 36.1 ± 4 kg/m². Group 2 (56 ± 6.7 yrs) had a BW of 238.8 ± 73.6 pounds and a BMI of 39.1 ± 9.3 kg/m2 (n.s. compared to group 1). All patients were alive at 12 months. At 6 months, BW in group 1 was reduced to 216.3 ± 20.8 pounds, and BMI to 31.8 ± 3.3 kg/m² (p < 0.05). At 6 months, BW in group 2 was 238.2 ± 84.6 pounds, and BMI was 39.1 ± 11.6 kg/m² (n.s. vs. baseline, p < 0.05 compared to group 1). The decrease in BW in group 1 was 12.3 ± 12% (30.3 ± 28.5 pounds). There was no change in BW in group 2 (0.3 ± 8.7%, 0.6 ± 21 pounds, p < 0.05 vs. group 1). At 12 months, 7 patients in group 1 (54%) underwent cardiac transplantation. LVAD insertion resulted in weight loss in obese patients not considered for heart transplantation compared to medically managed patients.

  12. Late right heart failure during support with continuous-flow left ventricular assist devices adversely affects post-transplant outcome.

    Science.gov (United States)

    Takeda, Koji; Takayama, Hiroo; Colombo, Paolo C; Jorde, Ulrich P; Yuzefpolskaya, Melana; Fukuhara, Shinichi; Mancini, Donna M; Naka, Yoshifumi

    2015-05-01

    Right heart failure (RHF) is an unresolved issue during continuous-flow left ventricular assist device (LVAD) support. Little is known about post-transplant outcomes in patients complicated by late RHF during LVAD support. Between May 2004 and December 2013, 141 patients underwent cardiac transplantation after isolated LVAD bridging at our center. Late RHF was defined as heart failure requiring medical intervention >4 weeks after LVAD implantation. The patients' mean age was 53 ± 13 years, 82% were men, and 36% had an ischemic etiology. The mean duration of LVAD support before transplantation was 0.75 years. Late RHF developed in 21 patients (15%) during LVAD support. Of these patients, 11 were supported with inotropic agents at the time of transplantation. Patients with RHF had higher creatinine (1.6 ± 0.88 mg/dL vs 1.3 ± 0.67 mg/dL, p = 0.07), higher blood urea nitrogen (32 ± 17 mg/dL vs 24 ± 10 mg/dL, p = 0.0013), higher total bilirubin (0.96 ± 0.46 mg/dL vs 0.78 ± 0.42 mg/dL, p = 0.07), and lower albumin (3.8 ± 0.60 g/dL vs 4.1 ± 0.46 g/dL, p = 0.0019) at the time of transplantation compared with patients who did not develop RHF. In-hospital mortality was significantly higher in patients with late RHF during LVAD support (29% vs 6.7%, p = 0.002). Overall post-transplant survival rates were 87% at 1 year, 83% at 3 years, and 77% at 5 years. The 5-year post-transplant survival was significantly worse in patients who developed late RHF during LVAD support compared with survival in patients who did not develop RHF (26% vs 87%, p RHF during LVAD support adversely affects post-transplant survival. Published by Elsevier Inc.

  13. Mental health status of patients with mechanical aortic valves, with ventricular assist devices and after heart transplantation.

    Science.gov (United States)

    Heilmann, Claudia; Kaps, Josefine; Hartmann, Armin; Zeh, Wolfgang; Anjarwalla, Anna Lena; Beyersdorf, Friedhelm; Siepe, Matthias; Joos, Andreas

    2016-08-01

    Mental health is a complex construct, in which emotional aspects and quality of life are central. It has been assessed in patients after heart transplantation (HTX) and occasionally in those with ventricular assist devices (VADs). However, there are no studies that compare patients with primary HTX with those with HTX ending VAD support. Evidence for patients with mechanical aortic valve replacement is also limited. We compared mental outcome for these four groups for the first time. We also focused on the question of an artificial device, i.e. VAD or mechanical aortic valve, as distinct from a biological graft, i.e. HTX. Two questionnaires were applied: The Hospital Anxiety and Depression Scale, the German version consists of two subscales for anxiety and for depression, and the 12-item Short Form Health Survey, the German version contains two subscales for physical and for mental performance measuring quality of life. We included 46 patients with mechanical aortic valve replacement, 55 after HTX and 22 on support by a long-term VAD. The HTX group consisted of 38 patients with primary HTX and 17 recipients who were on VAD support before transplantation. The index operation was at least 6 months ago. HTX patients suffered less from anxiety and depression than patients with mechanical aortic valve replacement or those on VAD. HTX patients had higher scores on the physical scale but not on the mental component scale of the 12-item Short Form Health Survey compared with VAD patients. Conversely, patients with mechanical aortic valve replacement did worse with regard to mental but not physical performance compared with HTX patients. VAD and mechanical aortic valve replacement patients differed only with regard to physical condition, but not with regard to anxiety, depression and mental status. HTX patients with and without VAD support before transplantation achieved similar values on all scales. Mental scales did not correlate with age or time after surgery. HTX

  14. Beneficial aspects of real time flow measurements for the management of acute right ventricular heart failure following continuous flow ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Spiliopoulos Sotirios

    2012-11-01

    Full Text Available Abstract Background Optimal management of acute right heart failure following the implantation of a left ventricular assist device requires a reliable estimation of left ventricular preload and contractility. This is possible by real-time pump blood flow measurements. Clinical case We performed implantation of a continuous flow left ventricular assist device in a 66 years old female patient with an end-stage heart failure on the grounds of a dilated cardiomyopathy. Real-time pump blood flow was directly measured by an ultrasonic flow probe placed around the outflow graft. Diagnosis The progressive decline of real time flow and the loss of pulsatility were associated with an increase of central venous pressure, inotropic therapy and progressive renal failure suggesting the presence of an acute right heart failure. Diagnosis was validated by echocardiography and thermodilution measurements. Treatment Temporary mechanical circulatory support of the right ventricle was successfully performed. Real time flow measurement proved to be a useful tool for the diagnosis and ultimately for the management of right heart failure including the weaning from extracorporeal membrane oxygenation.

  15. Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant

    Directory of Open Access Journals (Sweden)

    Despotis George J

    2007-07-01

    Full Text Available Abstract Background Ventricular assist devices(VAD implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT and/or VAD implantation. Methods A retrospective review was conducted from Jan 03 to Aug 05 for patients who received rFVIIa for the management of intractable bleeding unresponsive to standard hemostatic blood component therapy. Blood loss and the quantity of blood products, prior to, and for at least 12 hours after, administration of rFVIIa were recorded. Results Mean patient age was 53, (38–64 yrs, mean dose of rFVIIa administered was 78.3 μg/kg (24–189 μg/kg in 1–3 doses. All patients received the drug either intraoperatively or within 6 hours of arrival in ICU. Mean transfusion requirements and blood loss were significantly reduced after rFVIIa administration (PRBC's; 16.9 ± 13.3 to 7.1 ± 6.9 units, FFP; 13.1 ± 8.2 to 4.1 ± 4.9 units, platelets; 4.0 ± 2.8 to 2.1 ± 2.2 units, p Conclusion In this review, there was a significant decrease in transfusion requirement and blood loss after rFVIIa administration. Although, 5/17 developed thromboembolic complications, these patients may have been at higher risk based on the multiple modality therapy used to manage intractable bleeding. Nevertheless, the exact role of rFVIIa with respect to development of thromboembolic complications cannot be clearly determined. Further investigation is needed to determine rFVIIa's safety and its effectiveness in improving postoperative morbidity and mortality.

  16. Comparative cost-effectiveness of the HeartWare versus HeartMate II left ventricular assist devices used in the United Kingdom National Health Service bridge-to-transplant program for patients with heart failure.

    Science.gov (United States)

    Pulikottil-Jacob, Ruth; Suri, Gaurav; Connock, Martin; Kandala, Ngianga-Bakwin; Sutcliffe, Paul; Maheswaran, Hendramoorthy; Banner, Nicholas R; Clarke, Aileen

    2014-04-01

    Patients with advanced heart failure may receive a left ventricular assist device (LVAD) as part of a bridge-to-transplant (BTT) strategy. The United Kingdom National Health Service (UK NHS) has financed a BTT program in which the predominant LVADs used have been the HeartMate II (HM II; Thoratec, Pleasanton, CA) and HeartWare (HW; HeartWare International, Inc. Framingham, MA). We aimed to compare the cost-effectiveness of the use of these within the NHS program. Individual patient data from the UK NHS Blood and Transplant Data Base were analyzed with Kaplan-Meier and competing outcomes methodologies. Outcomes were time to death, time to heart transplant (HT), and cumulative incidences of HT, death on LVAD support, and LVAD explantation. A semi-Markov multistate economic model was built to assess cost-effectiveness. The perspective was from the NHS, discount rates were 3.5%. Outcomes were quality-adjusted life-years (QALYs) and incremental cost (2011 prices in GB£) per QALY (ICER) for HW vs HM II. Survival was better with HW support than with HM II. Cumulative incidence of HT was low for both groups (11% at ~2 years). HW patients accrued 4.99 lifetime QALYs costing £258,913 ($410,970), HM II patients accrued 3.84 QALYs costing £231,871 ($368,048); deterministic and probabilistic ICERs for HW vs HM II were £23,530 ($37,349) and £20,799 ($33,014), respectively. Patients In the UK BTT program who received the HW LVAD had a better clinical outcome than those who received the HM II, and the HW was more cost-effective. This result needs to be reassessed in a randomized controlled trial comparing the 2 devices. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  17. The Application of Bileaflet Mechanical Heart Valves in the Polish Ventricular Assist Device: Physical and Numerical Study and First Clinical Usage.

    Science.gov (United States)

    Malota, Zbigniew; Sadowski, Wojciech; Krzyskow, Marek; Stolarzewicz, Bogdan

    2016-03-01

    The Polish ventricular assist device (Polvad) has been used successfully in clinical contexts for many years. The device contains two single-disc valves, one at the inlet and one at the outlet connector of the pneumatic pump. Unfortunately, in recent years, a problem has occurred with the availability of single-disc valves. This article presents the possibility of using bileaflet mechanical heart valve prostheses in the Polvad to avoid a discontinuity in clinical use. The study is based on experimental and numerical simulations and comparison of the distribution of flow, pressure, and stress (wall, shear, and turbulent) inside the Polvad chamber and the inlet/outlet connectors fitted with Sorin Monodisc and Sorin Bicarbon Fitline valves. The type and orientation of the inlet valve affects valve performance and flow distribution inside the chamber. Near-wall flow is observed for single-disc valves. In the case of bileaflet valves, the main jet is directed more centrally, with lower shear stress but higher turbulent stress in comparison with single-disc valves. For clinical usage, a 45° orientation of the bileaflet inlet valve was chosen, as this achieves good washing of the inlet area near the membrane paste surface. The Polvad with bileaflet valves has now been used successfully in our clinic for over a year and will continue to be used until new assist devices for heart support are developed. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  18. Incidence of ventricular arrhythmias in patients on long-term support with a continuous-flow assist device (HeartMate II)

    DEFF Research Database (Denmark)

    Andersen, Mads; Videbaek, Regitze; Boesgaard, Søren

    2009-01-01

    The incidence of ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients supported with a continuous-flow left ventricular assist device (LVAD) has not been investigated in detail. In 23 consecutive recipients of a HeartMate II, we analyzed the incidence of VT/VF during a total...... of 266 months of follow-up. Sustained VT or VF occurred in 52% of the patients, with the majority of arrhythmias occurring in the first 4 weeks after LVAD implantation. VT/VF requiring implantable cardioverter-defibrillator (ICD) shock or external defibrillation occurred in 8 patients and significant...

  19. Derived and displayed power consumption, flow, and pulsatility over a range of HeartMate II left ventricular assist device settings.

    Science.gov (United States)

    Lund, Lars H; Gabrielsen, Anders; Tirén, Linnea; Hallberg, Ann; El Karlsson, Kerstin; Eriksson, Maria J

    2012-01-01

    Continuous-flow left ventricular assist devices/systems (LVADs/LVASs) reduce symptoms and mortality in severe heart failure. The impeller or centrifugal designs provide challenges in assessing and titrating pump speed (revolutions per minute [RPM]), flow, and native heart pulsatility, and contribution to cardiac output. The Thoratec HeartMate II (HM II) LVAS is the most commonly used LVAD worldwide. The user sets the RPM and the monitor provides online data on RPM, power consumption, flow, and pulsatility. These parameters are routinely used by clinicians to assess native heart function and to optimize pump settings. However, little is known about their reliability, reproducibility, and variability. Therefore, we assessed HM II controller parameters and concurrent echocardiography during titrations of RPM to low and high values. We found that data displayed on the monitor and logged in the controller are consistent for power consumption and for flow at settings above 8,000 RPM but inconsistent and unreliable for flow at or below 8,000 RPM and for pulsatility throughout a range of common settings and specifically at 9,000 RPM. These findings have implications for clinicians attempting to optimize settings and assess pump and native heart function.

  20. Derivation and Validation of a Novel Right-Sided Heart Failure Model After Implantation of Continuous Flow Left Ventricular Assist Devices:The EUROMACS (European Registry for Patients with Mechanical Circulatory Support) Right-Sided Heart Failure Risk Score.

    Science.gov (United States)

    Soliman, Osama I; Akin, Sakir; Muslem, Rahatullah; Boersma, Eric; Manintveld, Olivier C; Krabatsch, Thomas; Gummert, Jan F; de By, Theo M M H; Bogers, Ad J J C; Zijlstra, Felix; Mohacsi, Paul; Caliskan, Kadir

    2017-08-27

    Background -The aim of the study was to derive and validate a novel risk score for early right-sided heart failure (RHF) after left ventricular assist device implantation. Methods -The European Registry for Patients with Mechanical irculatory Support (EUROMACS) was used to identify adult patients undergoing continuous-flow left ventricular assist device implantation with mainstream devices. Eligible patients (n=2988) were randomly divided into derivation (n=2000) and validation (n=988) cohorts. The primary outcome was early (RHF, defined as receiving short- or long-term rightsided circulatory support, continuous inotropic support for ≥14 days, or nitric oxide ventilation for ≥48 hours. The secondary outcome was all-cause mortality and length of stay in the intensive care unit. Covariates found to be associated with RHF (exploratory univariate PRHF in the derivation cohort occurred in 433 patients (21.7%) after left ventricular assist device implantation and was associated with a lower 1-year (53% versus 71%; PRHF. RHF risk ranged from 11% (low risk score 0-2) to 43.1% (high risk score >4; PRHF, respectively (PRHF risk score outperformed (PRHF. Conclusions -This novel EUROMACS-RHF risk score outperformed currently known risk scores and clinical predictors of early postoperative RHF. This novel score may be useful for tailored risk-based clinical assessment and management of patients with advanced HF evaluated for ventricular assist device therapy.

  1. Body position and activity, but not heart rate, affect pump flows in patients with continuous-flow left ventricular assist devices.

    Science.gov (United States)

    Muthiah, Kavitha; Gupta, Sunil; Otton, James; Robson, Desiree; Walker, Robyn; Tay, Andre; Macdonald, Peter; Keogh, Anne; Kotlyar, Eugene; Granger, Emily; Dhital, Kumud; Spratt, Phillip; Jansz, Paul; Hayward, Christopher S

    2014-08-01

    The aim of this study was to determine the contribution of pre-load and heart rate to pump flow in patients implanted with continuous-flow left ventricular assist devices (cfLVADs). Although it is known that cfLVAD pump flow increases with exercise, it is unclear if this increment is driven by increased heart rate, augmented intrinsic ventricular contraction, or enhanced venous return. Two studies were performed in patients implanted with the HeartWare HVAD. In 11 patients, paced heart rate was increased to approximately 40 beats/min above baseline and then down to approximately 30 beats/min below baseline pacing rate (in pacemaker-dependent patients). Ten patients underwent tilt-table testing at 30°, 60°, and 80° passive head-up tilt for 3 min and then for a further 3 min after ankle flexion exercise. This regimen was repeated at 20° passive head-down tilt. Pump parameters, noninvasive hemodynamics, and 2-dimensional echocardiographic measures were recorded. Heart rate alteration by pacing did not affect LVAD flows or LV dimensions. LVAD pump flow decreased from baseline 4.9 ± 0.6 l/min to approximately 4.5 ± 0.5 l/min at each level of head-up tilt (p heart rate, but they change significantly with body position and passive filling. Previously demonstrated exercise-induced changes in pump flows may be related to altered loading conditions, rather than changes in heart rate. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  2. Accuracy of Seattle Heart Failure Model and HeartMate II Risk Score in Non-Inotrope-Dependent Advanced Heart Failure Patients: Insights From the ROADMAP Study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients).

    Science.gov (United States)

    Lanfear, David E; Levy, Wayne C; Stehlik, Josef; Estep, Jerry D; Rogers, Joseph G; Shah, Keyur B; Boyle, Andrew J; Chuang, Joyce; Farrar, David J; Starling, Randall C

    2017-05-01

    Timing of left ventricular assist device (LVAD) implantation in advanced heart failure patients not on inotropes is unclear. Relevant prediction models exist (SHFM [Seattle Heart Failure Model] and HMRS [HeartMate II Risk Score]), but use in this group is not established. ROADMAP (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management in Ambulatory Heart Failure Patients) is a prospective, multicenter, nonrandomized study of 200 advanced heart failure patients not on inotropes who met indications for LVAD implantation, comparing the effectiveness of HeartMate II support versus optimal medical management. We compared SHFM-predicted versus observed survival (overall survival and LVAD-free survival) in the optimal medical management arm (n=103) and HMRS-predicted versus observed survival in all LVAD patients (n=111) using Cox modeling, receiver-operator characteristic (ROC) curves, and calibration plots. In the optimal medical management cohort, the SHFM was a significant predictor of survival (hazard ratio=2.98; P heart failure patients receiving optimal medical management, the SHFM was predictive of overall survival but underestimated the risk of clinical worsening and LVAD implantation. Among LVAD patients, the HMRS had marginal discrimination and underestimated survival post-LVAD implantation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01452802. © 2017 American Heart Association, Inc.

  3. Cost-effectiveness of left ventricular assist devices for patients with end-stage heart failure: analysis of the French hospital discharge database.

    Science.gov (United States)

    Tadmouri, Abir; Blomkvist, Josefin; Landais, Cécile; Seymour, Jerome; Azmoun, Alexandre

    2017-07-25

    Although left ventricular assist devices (LVADs) are currently approved for coverage and reimbursement in France, no French cost-effectiveness (CE) data are available to support this decision. This study aimed at estimating the CE of LVAD compared with medical management in the French health system. Individual patient data from the 'French hospital discharge database' (Medicalization of information systems program) were analysed using Kaplan-Meier method. Outcomes were time to death, time to heart transplantation (HTx), and time to death after HTx. A micro-costing method was used to calculate the monthly costs extracted from the Program for the Medicalization of Information Systems. A multistate Markov monthly cycle model was developed to assess CE. The analysis over a lifetime horizon was performed from the perspective of the French healthcare payer; discount rates were 4%. Probabilistic and deterministic sensitivity analyses were performed. Outcomes were quality-adjusted life years (QALYs) and incremental CE ratio (ICER). Mean QALY for an LVAD patient was 1.5 at a lifetime cost of €190 739, delivering a probabilistic ICER of €125 580/QALY [95% confidence interval: 105 587 to 150 314]. The sensitivity analysis showed that the ICER was mainly sensitive to two factors: (i) the high acquisition cost of the device and (ii) the device performance in terms of patient survival. Our economic evaluation showed that the use of LVAD in patients with end-stage heart failure yields greater benefit in terms of survival than medical management at an extra lifetime cost exceeding the €100 000/QALY. Technological advances and device costs reduction shall hence lead to an improvement in overall CE. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  4. Failure Strain and Strain-Stress Analysis in Titanium Nitride Coatings Deposited on Religa Heart Ext Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Kopernik M.

    2015-04-01

    Full Text Available The Polish ventricular assist device is made of Bionate II with deposited TiN biocompatible nano-coating. The two scale finite element model is composed of a macro-model of blood chamber and a micro-model of the TiN/Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture. Therefore, the identification of a fracture parameter considered as a failure strain is the purpose of the present work. The tensile test in a micro chamber of the SEM was performed to calibrate the fracture parameter of the material system TiN/Bionate II. The failure strain is a function of a temperature, a thickness of coating and parameters of surface's profile. The failure strain was calculated at the stage of the test, in which the initiation of fracture occurred. The finite element micro-model includes the surface roughness and the failure strain under tension condition for two thicknesses of coatings which will be deposited on the medical device.

  5. Comparison of Mechanical Circulatory Support by the Use of Pulsatile Left Ventricular Assist Devices Polvad MEV and Continuous Flow Heart Ware and Heart Mate II in a Single-Center Experience.

    Science.gov (United States)

    Nadziakiewicz, P; Pacholewicz, J; Zakliczynski, M; Niklewski, T; Borkowski, J; Hrapkowicz, T; Zembala, M

    2016-06-01

    Mechanical circulatory support is increasingly used in patients with heart failure as a bridge to transplant or recovery. Results of use the Polish POLVAD MEV pulsatile circulatory support system and its comparison with novel devices never was done. We compared the course of patients with left ventricular circulatory support (left ventricular assist device [LVAD]) supported by POLVAD MEV or continuous flow devices Heart Mate II (HM II) and Heart Ware (HW) in single-center cohort. We retrospectively reviewed 44 patients who underwent Polvad Mev (group P; n = 24 [21M/3F]) or HW or HM II (group C; n = 20 [20M/0F]) implantation between April 2007 and February 2014. Patients were in INTERMACS 1 (6 in group P and 1 in group C) or 2. Preimplant demographics, and perioperative and postoperative clinical outcomes were reviewed between groups. We analyzed baseline signs of heart failure, comorbidities, complications, and the 30- and 90-day results. Among the groups, age, gender, weight, and cause of heart failure were comparable. Patients in group C suffered more frequently from hypercholesterolemia preoperatively. Patients in group P had more pulmonary complications (7 vs 0) after LVAD implantation and stay longer on intensive care unit than patients in group C (17.61 ± 16.96 vs 9.56 ± 9.42; P = .047). After exclusion, INTERMACS 1 patients it was not significant (14.8 ± 10.8 vs 9.8 ± 9.6 days; P = .065), the 30- and 90-day mortality was comparable. Implantation of pulsatile POLVAD MEV and continuous flow devices as LVAD support provides comparable results. A greater number of complications in group P can cause increased mortality over a longer observation period. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Correlation of Pre-Explant Lactate Dehydrogenase Concentrations and Findings During Post-Explant Pump Analysis of the HeartMate II Left Ventricular Assist Device.

    Science.gov (United States)

    Sood, Vikram; Alam, Osman; Tchantchaleishvili, Vakhtang; Pagani, Francis D; Aaronson, Keith D; Haft, Jonathan; Joyce, David L; Joyce, Lyle D; Daly, Richard C; Maltais, Simon; Stulak, John M

    2017-04-01

    Analyses of the HeartMate II left ventricular assist device are routinely performed after explant if returned to the manufacturer. Findings from manufacturer-reported pump analyses have not been correlated with pre-explant serum lactate dehydrogenase (LDH) values. Between May 2004 and December 2014, 502 patients underwent primary HeartMate II implantation. Seventy pumps were explanted in 58 patients and returned to the manufacturer for pump analysis: 51 (73%) for suspected pump thrombosis, 12 (17%) for device-related infection, and 7 (13%) for percutaneous lead fracture. Median time from implant to explant was 12.4 months (range, 1 to 57 months). Pump thrombus was confirmed in 53 of 70 pumps (76%). Stratified by major clinical indications for explant of suspected pump thrombus or infection and lead fracture, the presence of pump thrombus was identified in 47 of 51 (92%) and 6 of 19 (32%), respectively. The median of 1) all LDH values, 2) maximum LDH values, and 3) interval change in LDH between 6 and 2 months before device explant were 1,061, 1,940, and -27 IU/L with thrombus present and 533, 504, and 13 IU/L in the absence of thrombus. Density estimation of LDH concentrations identified that a LDH value of 1,155 IU/L in the 6 months preceding pump thrombus had a 78% sensitivity and 90% specificity for findings of pump thrombus at the time of pump analysis. Pre-explant LDH concentrations significantly correlated with findings on manufacture-performed pump analysis. These data validate LDH surveillance as an important clinical tool for identification of pump thrombus. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Exercise Capacity and Functional Performance in Heart Failure Patients Supported by a Left Ventricular Assist Device at Discharge From Inpatient Rehabilitation.

    Science.gov (United States)

    Schmidt, Thomas; Bjarnason-Wehrens, Birna; Bartsch, Petra; Deniz, Ezin; Schmitto, Jan; Schulte-Eistrup, Sebastian; Willemsen, Detlev; Reiss, Nils

    2017-06-16

    Adequate physical and functional performance is an important prerequisite for renewed participation and integration in self-determined private and (where appropriate) professional lives following left ventricular assist device (LVAD) implantation. During cardiac rehabilitation (CR), individually adapted exercise programs aim to increase exercise capacity and functional performance. A retrospective analysis of cardiopulmonary exercise capacity and functional performance in LVAD patients at discharge from a cardiac rehabilitation program was conducted. The results from 68 LVAD patients (59 males, 9 females; 55.9 ± 11.7 years; 47 HVAD, 2 MVAD, 15 HeartMate II, 4 HeartMate 3, and 4 different implanting centers) were included in the analysis. Exercise capacity was assessed using a cardiopulmonary exercise test on a bicycle ergometer (ramp protocol; 10 W/min). The 6-min walk test was used to determine functional performance. At discharge from CR (53 ± 17 days after implantation), the mean peak work load achieved was 62.2 ± 19.3 W (38% of predicted values) or 0.79 ± 0.25 W/kg body weight. The mean cardiopulmonary exercise capacity (relative peak oxygen uptake) was 10.6 ± 5.3 mL/kg/min (37% of predicted values). The 6-min walk distance improved significantly during CR (325 ± 106 to 405 ± 77 m; P exercise capacity remains considerably restricted. In contrast, functional performance, measured by the 6-min walk distance, reaches an acceptable level. Light everyday tasks seem to be realistically surmountable for patients, making discharge from inpatient rehabilitation possible. Long-term monitoring is required in order to evaluate the situation and how it develops further. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  8. Assessing the potential of e-mail for communicating drug therapy recommendations to physicians in patients with heart failure and ventricular-assist devices.

    Science.gov (United States)

    Lekura, Jona; Tita, Cristina; Lanfear, David E; Williams, Celeste T; Jennings, Douglas L

    2014-10-01

    This project explores electronic mail (e-mail) as a potential medium for pharmacists to communicate pharmacotherapy interventions to prescribers. This retrospective descriptive analysis was conducted at an urban, academic teaching hospital. The pharmacist attempted a drug therapy intervention via e-mail when unable to make face-to-face contact with the attending physician. Eligible patients for this project were admitted to the advanced heart failure (HF) team between December 1, 2010, and July 31, 2011, and had at least 1 attempted e-mail intervention. The primary outcome was the number of accepted interventions, while the secondary end point was the time until a physician e-mail response. A total of 51 e-mail interventions were attempted on 29 patients (mean age = 53, 24% caucasian, 59% male, 69% left ventricular-assist device [VAD]). Overall, of the total 51 interventions,44 (86.3%) were accepted. The average time to a physician e-mail response was 41 minutes. Initiation of drug therapy and changing dose and route or frequency accounted for the most frequent intervention (33%). The most common drug classes involved in the e-mail interventions were angiotensin-converting enzyme inhibitors (15.7%), loop diuretics (9.8%), and antiplatelet agents (7.8%). Clinical pharmacists with well-established physician relationships can effectively implement timely drug therapy recommendations using e-mail communications in patients with advanced HF or VADs. © The Author(s) 2013.

  9. Frailty and Clinical Outcomes in Advanced Heart Failure Patients Undergoing Left Ventricular Assist Device Implantation: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Tse, Gary; Gong, Mengqi; Wong, Sunny Hei; Wu, William K K; Bazoukis, George; Lampropoulos, Konstantinos; Wong, Wing Tak; Xia, Yunlong; Wong, Martin C S; Liu, Tong; Woo, Jean

    2017-11-09

    Frailty has been identified as a risk factor for adverse clinical outcomes after cardiac intervention or surgery. However, whether it increases the risk of adverse outcomes in patients undergoing left ventricular assist device (LVAD) therapy has been controversial. Therefore, we conducted a systematic review and meta-analysis of the frailty measures and clinical outcomes of length of stay and mortality in this setting. PubMed and Embase were searched until September 11, 2017, for studies evaluating the association between frailty and clinical outcomes in advanced heart failure patients undergoing LVAD implantation. A total of 46 and 79 entries were retrieved from our search strategy. A total of 13 studies involving 3435 patients were included in the final meta-analysis (mean age: 57.7 ± 15.3 years; 79% male, follow-up duration was 13 ± 14 months). Compared to nonfrail patients (n = 2721), frail patients (n = 579) had significantly longer time-to-extubation (n = 3; mean difference: 45 ± 6 hours; I(2): 0%) and hospital length of stay (n = 4; mean difference: 2.9 ± 1.2 days; P = .001; I(2): 21%). Frailty was not a predictor of inpatient or short-term mortality [n = 3; hazard ratio (HR): 1.22, 95% confidence interval (CI): 0.66-2.26; P > .05; I(2): 0%] but predicted long-term mortality (n = 7; HR: 1.44, 95% CI: 1.15-1.80; P = .001; I(2): 0%). Frailty leads to significantly longer time to extubation, hospital length of stay, and long-term mortality in advanced heart failure patients who have undergone LVAD implantation. Older patients being considered for LVAD implantation should therefore be assessed for frailty status. The risk and benefit of the procedure should be explained to the patient, emphasizing that frailty increases the likelihood of adverse clinical outcomes. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  10. Patient-Reported Health-Related Quality of Life Is a Predictor of Outcomes in Ambulatory Heart Failure Patients Treated With Left Ventricular Assist Device Compared With Medical Management: Results From the ROADMAP Study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management).

    Science.gov (United States)

    Stehlik, Josef; Estep, Jerry D; Selzman, Craig H; Rogers, Joseph G; Spertus, John A; Shah, Keyur B; Chuang, Joyce; Farrar, David J; Starling, Randall C

    2017-06-01

    The prospective observational ROADMAP study (Risk Assessment and Comparative Effectiveness of Left Ventricular Assist Device and Medical Management) demonstrated that ambulatory advanced heart failure patients selected for left ventricular assist device (LVAD) were more likely to be alive at 1 year on original therapy with ≥75-m improvement in 6-minute walk distance compared with patients assigned to optimal medical management. Whether baseline health-related quality of life (hrQoL) resulted in a heterogeneity of this treatment benefit is unknown. Patient-reported hrQoL was assessed with EuroQol questionnaire and visual analogue scale (VAS). We aimed to identify predictors of event-free survival and survival with acceptable hrQoL (VAS≥60). LVAD patients had significant improvement in 3 of 5 EuroQol dimensions ( P heart failure patients with low self-reported hrQoL, but not in patients with acceptable quality of life at the time of LVAD implantation. Patient-reported hrQoL should be integrated into decision making concerning the use and timing of LVAD therapy in heart failure patients who are symptom limited but remain ambulatory. URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01452802. © 2017 American Heart Association, Inc.

  11. Design and performance of heart assist or artificial heart control systems

    Science.gov (United States)

    Webb, J. A., Jr.; Gebben, V. D.

    1978-01-01

    The factors leading to the design of a controlled driving system for either a heart assist pump or artificial heart are discussed. The system provides square pressure waveform to drive a pneumatic-type blood pump. For assist usage the system uses an R-wave detector circuit that can detect the R-wave of the electrocardiogram in the presence of electrical disturbances. This circuit provides a signal useful for synchronizing an assist pump with the natural heart. It synchronizes a square wave circuit, the output of which is converted into square waveforms of pneumatic pressure suitable for driving both assist device and artificial heart. The pressure levels of the driving waveforms are controlled by means of feedback channels to maintain physiological regulation of the artificial heart's output flow. A more compact system that could achieve similar regulatory characteristics is also discussed.

  12. An updated review of cardiac devices in heart failure.

    Science.gov (United States)

    Murphy, C; Zafar, H; Sharif, F

    2017-11-01

    Heart failure has the highest rates of adult hospitalisations, the highest mortality rates and significant costs associated with its care. The cost of heart failure is expected continue to grow on a global scale, with $108 billion spent on heart failure in 2012. Mortality rates are high, with incident cases of heart failure resulting in 30% 1-year mortality, and in hospital mortality of acute heart failure, 28%. This article reviews the devices currently in use for the treatment of heart failure, as well as those that are under investigation. A review of the mechanism of action of devices, the literature supporting their application as therapy, and the cost effectiveness associated with their use are discussed. Conventional techniques discussed herein include the guideline-supported therapies of mechanical circulatory support (MCS) and cardiac resynchronisation therapy (CRT). Novel devices that are discussed include invasive physiological monitoring, neuromodulation, percutaneous ventricular assist devices (VADs) and cardiac contractility modulation (CCM). There has been advancement in mechanical circulatory support devices for the treatment of both acute and chronic heart failure. In addition to MCS, only CRT has resulted in reduced mortality. Due to the clinical and economic arguments, treatment of heart failure is said to be the biggest unmet need in cardiology today. The data reviewed herein support this statement.

  13. Left Ventricular Assist Devices: The Adolescence of a Disruptive Technology.

    Science.gov (United States)

    Pinney, Sean P

    2015-10-01

    Clinical outcomes for patients with advanced heart failure receiving left ventricular assist devices are driven by appropriate patient selection, refined surgical technique, and coordinated medical care. Perhaps even more important is innovative pump design. The introduction and widespread adoption of continuous-flow ventricular assist devices has led to a paradigm shift within the field of mechanical circulatory support, making the promise of lifetime device therapy closer to reality. The disruption caused by this new technology, on the one hand, produced meaningful improvements in patient survival and quality of life, but also introduced new clinical challenges, such as bleeding, pump thrombosis, and acquired valvular heart disease. Further evolution within this field will require financial investment to sustain innovation leading to a fully implantable, durable, and cost-effective pump for a larger segment of patients with advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Assistive Devices: MedlinePlus Health Topic

    Science.gov (United States)

    ... Also in Spanish Rehabilitation Engineering: What is Rehabilitation Engineering? (National Institute of Biomedical Imaging and Bioengineering) ... (Transportation Security Administration) What Are Some Types of Assistive Devices and ...

  15. Cerebrovascular accidents in patients with a ventricular assist device.

    Science.gov (United States)

    Tsukui, Hiroyuki; Abla, Adib; Teuteberg, Jeffrey J; McNamara, Dennis M; Mathier, Michael A; Cadaret, Linda M; Kormos, Robert L

    2007-07-01

    A cerebrovascular accident is a devastating adverse event in a patient with a ventricular assist device. The goal was to clarify the risk factors for cerebrovascular accident. Prospectively collected data, including medical history, ventricular assist device type, white blood cell count, thrombelastogram, and infection, were reviewed retrospectively in 124 patients. Thirty-one patients (25%) had 48 cerebrovascular accidents. The mean ventricular assist device support period was 228 and 89 days in patients with and without cerebrovascular accidents, respectively (P cerebrovascular accidents occurred within 4 months after implantation. Actuarial freedom from cerebrovascular accident at 6 months was 75%, 64%, 63%, and 33% with the HeartMate device (Thoratec Corp, Pleasanton, Calif), Thoratec biventricular ventricular assist device (Thoratec Corp), Thoratec left ventricular assist device (Thoratec), and Novacor device (WorldHeart, Oakland, Calif), respectively. Twenty cerebrovascular accidents (42%) occurred in patients with infections. The mean white blood cell count at the cerebrovascular accident was greater than the normal range in patients with infection (12,900/mm3) and without infection (9500/mm3). The mean maximum amplitude of the thrombelastogram in the presence of infection (63.6 mm) was higher than that in the absence of infection (60.7 mm) (P = .0309). The risk of cerebrovascular accident increases with a longer ventricular assist device support period. Infection may activate platelet function and predispose the patient to a cerebrovascular accident. An elevation of the white blood cell count may also exacerbate the risk of cerebrovascular accident even in patients without infection. Selection of device type, prevention of infection, and meticulous control of anticoagulation are key to preventing cerebrovascular accident.

  16. Assistive Devices for Students with Disabilities.

    Science.gov (United States)

    Wisniewski, Lech; Sedlak, Robert

    1992-01-01

    Describes a variety of devices that can assist students with disabilities. Highlights recently developed devices for students with specific learning disabilities, and with vision, hearing, health, physical, and speech and language impairments. The devices can help rehabilitate, reeducate, facilitate normalcy, or augment current functioning. (GLR)

  17. Past and present of cardiocirculatory assist devices: a comprehensive critical review

    Science.gov (United States)

    Rigatelli, Gianluca; Santini, Francesco; Faggian, Giuseppe

    2012-01-01

    During the last 20 years, the management of heart failure has significantly improved by means of new pharmacotherapies, more timely invasive treatments and device assisted therapies. Indeed, advances in mechanical support, namely with the development of more efficient left ventricular assist devices (LVADs), and the total artificial heart have reduced mortality and morbidity in patients awaiting transplantation, so much so, that LVADs are now approved of as a strategy for destination therapy. In this review, the authors describe in detail the current basic indications, functioning modalities, main limitations of surgical LAVDs, total artificial heart development, and percutaneous assist devices, trying to clarify this complex, but fascinating topic. PMID:23341844

  18. Continuous-flow Left Ventricular Assist Devices: Clinical and Technical Aspects

    NARCIS (Netherlands)

    Martina, J.R.

    2013-01-01

    In view of the shortage of donor hearts, continuous-flow Left Ventricular Assist Devices (cf-LVADs) have become an effective therapeutic option to bridge heart failure patients to heart transplantation. The subject of this thesis is the clinical and technical aspects of continuous-flow Left

  19. Content Analysis of Social Media Related to Left Ventricular Assist Devices

    National Research Council Canada - National Science Library

    Kostick, Kristin M; Blumenthal-Barby, Jennifer S; Wilhelms, Lidija A; Delgado, Estevan D; Bruce, Courtenay R

    2015-01-01

    ... decisional and support needs. We conducted a mixed method study, including content analysis of social media and principal components analysis analysis of data sites discussing left ventricular assist device treatment for heart failure...

  20. 21 CFR 890.5050 - Daily activity assist device.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5050 Daily activity assist device. (a) Identification. A daily activity assist device is a modified adaptor or utensil (e.g... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Daily activity assist device. 890.5050 Section 890...

  1. Shock from heart device often triggers further health care needs

    Science.gov (United States)

    ... heart device often triggers further health care needs American Heart Association Rapid Access Journal Report February 14, 2017 Categories: ... published in Circulation: Cardiovascular Quality and Outcomes , an American Heart Association journal. ICDs save people from sudden cardiac death ...

  2. A Review of Ethical Considerations for Ventricular Assist Device Placement in Older Adults

    OpenAIRE

    Bruce, Courtenay R.

    2013-01-01

    This article reviews some of the complex ethical issues that accompany the diffusion of ventricular assist devices (VADs) for heart failure patients, with a particular emphasis on issues unique to older adults. In doing so, the ethical issues are centered on three decision points: (a) patient selection; (b) informed consent (i.e., initiation of the device); and (c) end of life (i.e., deactivation of the device.) It is contended that, with the technological improvements in heart failure treatm...

  3. Evaluating Personal Assistants on Mobile devices

    OpenAIRE

    Kiseleva, Julia; de Rijke, Maarten

    2017-01-01

    The iPhone was introduced only a decade ago in 2007 but has fundamentally changed the way we interact with online information. Mobile devices differ radically from classic command-based and point-and-click user interfaces, now allowing for gesture-based interaction using fine-grained touch and swipe signals. Due to the rapid growth in the use of voice-controlled intelligent personal assistants on mobile devices, such as Microsoft's Cortana, Google Now, and Apple's Siri, mobile devices have be...

  4. Hydrodynamic characterisation of ventricular assist devices

    NARCIS (Netherlands)

    Vandenberghe, S; Segers, P; Meyns, B; Verdonck, P

    A new mock circulatory system (MCS) was designed to evaluate and characterise the hydraulic performance of ventricular assist devices (VADs). The MCS consists of a preload section and a multipurpose afterload section, with an adjustable compliance chamber (C) and peripheral resistor (Rd as principal

  5. Feasibility of Robotic-Assisted Laparoscopic Nephroureterectomy in Left Ventricular Assist Device Patient

    Directory of Open Access Journals (Sweden)

    Tariq A. Khemees

    2012-01-01

    Full Text Available Left ventricular assist devices (LVADs have revolutionized management options for patients with advanced heart failure. It is not uncommon for patients treated with these devices to present with noncardiac surgical conditions including urologic problems. Maintaining perioperative hemodynamic and hematologic stability is a special challenge. The minimally invasive surgery provides well-documented advantages over the open approach including a less operative blood loss and faster convalescence. In carefully selected patients, robotic-assisted surgery can be utilized in the management of patients with complex urologic diseases in a dire need for these benefits. We present the first case of robotic-assisted laparoscopic nephroureterectomy (RANU with retroperitoneal lymph node dissection for upper tract transitional cell carcinoma (TCC in a patient treated with LVAD.

  6. Assistive technology devices: abandonment related factors

    Directory of Open Access Journals (Sweden)

    Celso Rodrigues da Costa

    2015-09-01

    Full Text Available This review aims to identify factors related to abandonment of assistive technology devices in face of the increased number of individuals with disabilities, as well as the importance of the assistive technology devices (ATD to improve their occupational performance, the increased abandonment rates of these devices and the high costs associated with them. We used a critical literature review with the keywords: assistive technology/tecnologia assistiva, abandonment/abandono, rejection/rejeição, and disuse/desuso, published between the years 2002 and 2013. The search was conducted in MEDLINE, LILACS and SciELO and identified a total of 49 articles and 9 publications that met the inclusion criterion. It found that the most cited factors related to the abandonment of devices are problems with the user’s physical condition; lack of information and training both professionals and users; pain; lack of functionality; ATD preference or other use of remaining capacity; increased weight; changes in ADT conditions; use difficulty; unsatisfactoriness; discomfort; inadequacy/inappropriate; and “lot of noise”. The better understanding of these factors is critical to improve the effectiveness of prescription and intervention by professionals and imperative to increase membership and promote effective results.

  7. Cataract surgery in patients with left ventricular assist device support.

    Science.gov (United States)

    Eghrari, Allen O; Rivers, Richard J; Alkharashi, Majed; Rajaii, Fatemeh; Nyhan, Daniel; Sikder, Shameema

    2014-04-01

    Left ventricular assist devices (LVADs) have been increasingly used for 20 years in terminally ill patients with advanced heart failure or awaiting cardiac transplantation. Despite improvement in morbidity and mortality from use of these devices, quality of life may be limited by cataract. Access to cataract surgery in this predominantly elderly population is essential but limited by unfamiliarity with these devices. We describe phacoemulsification and intraocular lens implantation in 2 patients with LVADs. The patients had extensive preoperative cardiology evaluations and were instructed to continue warfarin through the day of surgery. Monitored sedation was used with fentanyl and midazolam. Both patients experienced significant improvement in visual acuity and quality of life. Neither experienced intraoperative hemodynamic instability. Cataract surgery may be safely performed in patients with LVAD support when adequate monitoring resources are available. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Clinical effectiveness and cost-effectiveness of second- and third-generation left ventricular assist devices as either bridge to transplant or alternative to transplant for adults eligible for heart transplantation: systematic review and cost-effectiveness model.

    Science.gov (United States)

    Sutcliffe, P; Connock, M; Pulikottil-Jacob, R; Kandala, N-B; Suri, G; Gurung, T; Grove, A; Shyangdan, D; Briscoe, S; Maheswaran, H; Clarke, A

    2013-11-01

    Advanced heart failure (HF) is a debilitating condition for which heart transplant (HT) offers the best treatment option. However, the supply of donor hearts is diminishing and demand greatly exceeds supply. Ventricular assist devices (VADs) are surgically implanted pumps used as an alternative to transplant (ATT) or as a bridge to transplant (BTT) while a patient awaits a donor heart. Surgery and VADs are costly. For the NHS to allocate and deliver such services in a cost-effective way the relative costs and benefits of these alternative treatments need to be estimated. To investigate for patients aged ≥ 16 years with advanced HF eligible for HT: (1) the clinical effectiveness and cost-effectiveness of second- and third-generation VADs used as BTT compared with medical management (MM); and (2) the clinical effectiveness and cost-effectiveness of second- and third-generation VADs used as an ATT in comparison with their use as BTT therapy. Searches for clinical effectiveness studies covered years from 2003 to March 2012 and included the following data bases: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), NHS Economic Evaluation Database (NHS EED), HTA databases [NHS Centre for Reviews and Dissemination (CRD)], Science Citation Index and Conference Proceedings (Web of Science), UK Clinical Research Network (UKCRN) Portfolio Database, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO and National Library of Medicine (NLM) Gateway, Cochrane Central Register of Controlled Trials (CENTRAL), Current Controlled Trials and ClinicalTrials.gov. Reference lists of relevant articles were checked, and VAD manufacturers' websites interrogated. For economic analyses we made use of individual patient data (IPD) held in the UK Blood and Transplant Database (BTDB). Systematic reviews of evidence on clinical effectiveness and cost

  9. Mechanical Circulatory Support Devices for Pediatric Patients With Congenital Heart Disease.

    Science.gov (United States)

    Chopski, Steven G; Moskowitz, William B; Stevens, Randy M; Throckmorton, Amy L

    2017-01-01

    The use of mechanical circulatory support (MCS) devices is a viable therapeutic treatment option for patients with congestive heart failure. Ventricular assist devices, cavopulmonary assist devices, and total artificial heart pumps continue to gain acceptance as viable treatment strategies for both adults and pediatric patients as bridge-to-transplant, bridge-to-recovery, and longer-term circulatory support alternatives. We present a review of the current and future MCS devices for patients having congenital heart disease (CHD) with biventricular or univentricular circulations. Several devices that are specifically designed for patients with complex CHD are in the development pipeline undergoing rigorous animal testing as readiness experiments in preparation for future clinical trials. These advances in the development of new blood pumps for patients with CHD will address a significant unmet clinical need, as well as generally improve innovation of the current state of the art in MCS technology. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  10. Mycobacterium chimaera left ventricular assist device infections.

    Science.gov (United States)

    Balsam, Leora B; Louie, Eddie; Hill, Fred; Levine, Jamie; Phillips, Michael S

    2017-06-01

    A global outbreak of invasive Mycobacterium chimaera infections after cardiac surgery has recently been linked to bioaerosols from contaminated heater-cooler units. The majority of cases have occurred after valvular surgery or aortic graft surgery and nearly half have resulted in death. To date, infections in patients with left ventricular assist devices (LVADs) have not been characterized in the literature. We report two cases of device-associated M. chimaera infection in patients with continuous-flow LVADs and describe challenges related to diagnosis and management in this population. © 2017 Wiley Periodicals, Inc.

  11. Changes in Spirometry After Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Mohamedali, Burhan; Bhat, Geetha; Yost, Gardner; Tatooles, Antone

    2015-12-01

    Left ventricular assist devices (LVADs) are increasingly being used as life-saving therapy in patients with end-stage heart failure. The changes in spirometry following LVAD implantation and subsequent unloading of the left ventricle and pulmonary circulation are unknown. In this study, we explored long-term changes in spirometry after LVAD placement. In this retrospective study, we compared baseline preoperative pulmonary function test (PFT) results to post-LVAD spirometric measurements. Our results indicated that pulmonary function tests were significantly reduced after LVAD placement (forced expiratory volume in one second [FEV1 ]: 1.9 vs.1.7, P = 0.016; forced vital capacity [FVC]: 2.61 vs. 2.38, P = 0.03; diffusing capacity of the lungs for carbon monoxide [DLCO]: 14.75 vs. 11.01, P = 0.01). Subgroup analysis revealed greater impairment in lung function in patients receiving HeartMate II (Thoratec, Pleasanton, CA, USA) LVADs compared with those receiving HeartWare (HeartWare, Framingham, MA, USA) devices. These unexpected findings may result from restriction of left anterior hemi-diaphragm; however, further prospective studies to validate our findings are warranted. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  12. The Physiology of Continuous-Flow Left Ventricular Assist Devices.

    Science.gov (United States)

    Lim, Hoong Sern; Howell, Neil; Ranasinghe, Aaron

    2017-02-01

    The use of left ventricular assist devices (LVADs) has increased significantly over the past few years, in part because heart transplant activity has plateaued, but also because of the improving clinical outcomes with contemporary continuous-flow LVAD. As such, there is now a growing population of patients with continuous-flow LVADs. Management of these patients is complicated by the altered circulatory physiology, because continuous-flow LVADs provide a parallel circulation from the heart to the aorta, which interacts with the native left heart (systemic) circulation with consequent effects on the right heart circulation. In addition, the displayed pump parameters can mislead the unwary clinician. An understanding of LVAD physiology can guide clinicians in the management of patients with LVADs. This review describes the basic design of axial and centrifugal continuous-flow LVADs, the functional anatomy and physiology of continuous-flow LVADs, and the interaction between the heart and the LVAD. leading to a discussion about the interpretation of the pump parameters in clinical practice. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Beyond the hearing aid: Assistive listening devices

    Science.gov (United States)

    Holmes, Alice E.

    2003-04-01

    Persons with hearing loss can obtain great benefit from hearing aids but there are many situations that traditional amplification devices will not provide enough help to ensure optimal communication. Assistive listening and signaling devices are designed to improve the communication of the hearing impaired in instances where traditional hearing aids are not sufficient. These devices are designed to help with problems created by listening in noise or against a competing message, improve distance listening, facilitate group conversation (help with problems created by rapidly changing speakers), and allow independence from friends and family. With the passage of the Americans with Disabilities Act in 1990, assistive listening devices (ALDs) are becoming more accessible to the public with hearing loss. Employers and public facilities must provide auxiliary aids and services when necessary to ensure effective communication for persons who are deaf or hard of hearing. However many professionals and persons with hearing loss are unaware of the various types and availability of ALDs. An overview of ALDs along with a discussion of their advantages and disadvantages will be given.

  14. Left Ventricular Assist Devices for Lifelong Support.

    Science.gov (United States)

    Pinney, Sean P; Anyanwu, Anelechi C; Lala, Anuradha; Teuteberg, Jeffrey J; Uriel, Nir; Mehra, Mandeep R

    2017-06-13

    Continuous-flow left ventricular assist devices (LVADs) have revolutionized advanced heart failure care. These compact, fully implantable heart pumps are capable of providing meaningful increases in survival, functional capacity, and quality of life. Implantation volumes continue to grow, but several challenges remain to be overcome before LVADs will be considered as the therapy of choice for all patients with advanced heart failure. They must be able to consistently extend survival for the long term (7 to 10 years), rather than the midterm (3 to 5 years) more typical of contemporary devices; they must incorporate design elements that reduce shear stress and avoid stasis to reduce the frequent adverse events of bleeding, stroke, and pump thrombosis; and they must become more cost-effective. The advancements in engineering, implantation technique, and medical management detailed in this review will highlight the progress made toward achieving lifelong LVAD support and the challenges that remain. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Brain-controlled body movement assistance devices and methods

    Energy Technology Data Exchange (ETDEWEB)

    Leuthardt, Eric C.; Love, Lonnie J.; Coker, Rob; Moran, Daniel W.

    2017-01-10

    Methods, devices, systems, and apparatus, including computer programs encoded on a computer storage medium, for brain-controlled body movement assistance devices. In one aspect, a device includes a brain-controlled body movement assistance device with a brain-computer interface (BCI) component adapted to be mounted to a user, a body movement assistance component operably connected to the BCI component and adapted to be worn by the user, and a feedback mechanism provided in connection with at least one of the BCI component and the body movement assistance component, the feedback mechanism being configured to output information relating to a usage session of the brain-controlled body movement assistance device.

  16. Psychological distress in patients with a left ventricular assist device and their partners

    DEFF Research Database (Denmark)

    Brouwers, Corline; Denollet, Johan; Caliskan, Kadir

    2015-01-01

    Background:Left ventricular assist device (LVAD) therapy is increasingly used in patients with advanced heart failure, and may have a significant psychological impact on both patients and their partners. Hence, we examined the distress levels of LVAD patients and their partners.Methods:Anxiety, d......Background:Left ventricular assist device (LVAD) therapy is increasingly used in patients with advanced heart failure, and may have a significant psychological impact on both patients and their partners. Hence, we examined the distress levels of LVAD patients and their partners...

  17. Pump Flow Estimation From Pressure Head and Power Uptake for the HeartAssist5, HeartMate II, and HeartWare VADs

    NARCIS (Netherlands)

    Pennings, Kim A. M. A.; Martina, Jerson R.; Rodermans, Ben F. M.; Lahpor, Jaap R.; van de Vosse, Frans N.; de Mol, Bas A. J. M.; Rutten, Marcel C. M.

    2013-01-01

    The use of long-term mechanical circulatory support (MCS) for heart failure by means of implanted continuous-flow left ventricular assist devices (cf-LVADs) will increase, either to enable recovery or to provide a destination therapy. The effectiveness and user-friendliness of MCS will depend on the

  18. Oxidative stress induced modulation of platelet integrin α2bβ3 expression and shedding may predict the risk of major bleeding in heart failure patients supported by continuous flow left ventricular assist devices.

    Science.gov (United States)

    Mondal, Nandan K; Chen, Zengsheng; Trivedi, Jaimin R; Sorensen, Erik N; Pham, Si M; Slaughter, Mark S; Griffith, Bartley P; Wu, Zhongjun J

    2017-10-01

    Oxidative stress and platelet integrin α2bβ3 plays important role in the process of hemostasis and thrombosis. We hypothesized that device-induced patient specific oxidative stress and integrin α2bβ3 shedding may be linked to major bleeding complication (MBC) in heart failure (HF) patients supported by continuous flow left ventricular assist devices (CF-LVADs). We recruited 47patients implanted with CF-LVADs and 15 healthy volunteers. Fourteen patients developed MBC (bleeder group) within one month after implantation while others were considered non-bleeder group (n=33). Oxidative stresses were evaluated by measuring reactive oxygen species (ROS) in platelets, superoxide dismutase (SOD) activity, total antioxidant capacity (TAC) and oxidized low density lipoprotein (oxLDL). Assessments of α2bβ3 were carried out using flow cytometry and ELISA. Biomarkers of oxidative stress and α2bβ3 shedding (decreased surface expression and higher plasma levels) were found to be preexisting condition in all HF patients prior to CF-LVAD implantation compared to the healthy volunteers. Significantly elevated levels of ROS and oxLDL; concomitant depletion of SOD and TAC; and α2bβ3 shedding were observed in the bleeder group temporarily in comparison to the non-bleeder group after CF-LVAD implantation. A significantly strong association between α2bβ3 shedding and biomarkers of oxidative stress was observed; suggesting a potential role of oxidative stress in platelet integrin shedding leading to MBC after CF-LVAD implantation. Moreover, a receiver operating characteristic (ROC) analysis indicated that the likelihood of MBC data from Integrin α2bβ3 shedding had a predictive power of MBC in CF-LVAD patients. Oxidative stress might play a potential role in accelerating α2bβ3 shedding and platelet dysfunction, resulting in MBC in CF-LVAD patients. Integrin α2bβ3 shedding may be used to refine bleeding risk stratification in CF-LVAD patients. Copyright © 2017 Elsevier Ltd

  19. Screening for heart transplantation and left ventricular assist system

    DEFF Research Database (Denmark)

    Lund, Lars H; Trochu, Jean-Noel; Meyns, Bart

    2018-01-01

    BACKGROUND: Heart transplantation (HTx) and implantable left ventricular assist systems (LVAS) improve outcomes in advanced heart failure but may be underutilized. We hypothesized that screening can identify appropriate candidates. METHODS AND RESULTS: The ScrEEning for advanced Heart Failure tre...

  20. DuraHeart magnetically levitated centrifugal left ventricular assist system for advanced heart failure patients.

    Science.gov (United States)

    Morshuis, Michiel; Schoenbrodt, Michael; Nojiri, Chisato; Roefe, Daniela; Schulte-Eistrup, Sebastian; Boergermann, Jochen; Gummert, Jan F; Arusoglu, Latif

    2010-03-01

    The implantable left ventricular assist system (LVAS) using pulsatile pump technology has become an established therapeutic option for advanced heart failure patients. However, there have been technological limitations in some older designs, including a high incidence of infection and mechanical failures associated with moving parts, and the large size of both implantable pump and percutaneous cable. A smaller rotary blood pump emerged as a possible alternative to a large pulsatile pump to overcome some of these limitations. The technological advancement that defines the third-generation LVAS was the elimination of all mechanical contacts between the impeller and the drive mechanism. The DuraHeart LVAS is the world's first third-generation implantable LVAS to obtain market approval (CE-mark), which combines a centrifugal pump and active magnetic levitation. The initial clinical experience with the DuraHeart LVAS in Europe demonstrated that it provided significantly improved survival (85% at 6 months and 79% at 1 year), reduced adverse event rates and long-term device reliability (freedom from device replacement at 2 years: 96 +/- 3%) over pulsatile LVAS.

  1. Getting a New Heart

    Science.gov (United States)

    ... a procedure that opens clogged arteries. Repair the heart valve . This procedure can often make your heart function ... heart muscle. Ventricular assist devices (VAD) . These are mechanical pumps that surgeons insert to help the heart ...

  2. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    OpenAIRE

    Fan Liang; Yang Yu; Haizhong Wang; Xiaofeng Meng

    2013-01-01

    Off-pump Coronary Artery Bypass Graft (CABG) surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track ...

  3. 76 FR 61655 - Definition of Part 15 Auditory Assistance Device

    Science.gov (United States)

    2011-10-05

    ... COMMISSION 47 CFR Part 15 Definition of Part 15 Auditory Assistance Device AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY: This document proposes to amend the definition of ``auditory... definition restricts the use of part 15 auditory assistance devices that operate in the 72.0-73.0 MHz, 74.6...

  4. Successful treatment of a continuous flow left ventricular assist device thrombosis with eptifibatide.

    Science.gov (United States)

    Jennings, Douglas L; Cabrera, Rafael; Wang, Dee Dee; Tita, Cristina

    2012-01-01

    Left ventricular assist device thrombosis is a rare but potentially lethal complication of mechanical circulatory support. Here, we present a case of successful treatment of a suspected HeartMate II thrombosis with the glycoprotein IIb/IIIa inhibitor, eptifibatide. The patient presented with signs and symptoms of heart failure, along with acute kidney injury and hemolytic anemia that did not respond to diuresis, inotrope support, or anticoagulation. Treatment with eptifibatide resulted in marked clinical and hemodynamic improvement within 24 hrs. The patient was transitioned to clopidogrel and discharged without further incident. Eptifibatide may represent a potential therapeutic option for patients with device thrombosis.

  5. Improving hemodynamics of cardiovascular system under a novel intraventricular assist device support via modeling and simulations.

    Science.gov (United States)

    Zhu, Shidong; Luo, Lin; Yang, Bibo; Li, Xinghui; Wang, Xiaohao

    2017-12-01

    Ventricular assist devices (LVADs) are increasingly recognized for supporting blood circulation in heart failure patients who are non-transplant eligible. Because of its volume, the traditional pulsatile device is not easy to implant intracorporeally. Continuous flow LVADs (CF-LVADs) reduce arterial pulsatility and only offer continuous flow, which is different from physiological flow, and may cause long-term complications in the cardiovascular system. The aim of this study was to design a new pulsatile assist device that overcomes this disadvantage, and to test this device in the cardiovascular system. Firstly, the input and output characteristics of the new device were tested in a simple cardiovascular mock system. A detailed mathematical model was established by fitting the experimental data. Secondly, the model was tested in four pathological cases, and was simulated and coupled with a fifth-order cardiovascular system and a new device model using Matlab software. Using assistance of the new device, we demonstrated that the left ventricle pressure, aortic pressure, and aortic flow of heart failure patients improved to the levels of a healthy individual. Especially, in state IV level heart failure patients, the systolic blood pressure increased from 81.34 mmHg to 132.1 mmHg, whereas the diastolic blood pressure increased from 54.28 mmHg to 78.7 mmHg. Cardiac output increased from 3.21 L/min to 5.16 L/min. The newly-developed assist device not only provided a physiological flow that was similar to healthy individuals, but also effectively improved the ability of the pathological ventricular volume. Finally, the effects of the new device on other hemodynamic parameters are discussed.

  6. Left ventricular assist device (lvad design features: literature review

    Directory of Open Access Journals (Sweden)

    Yu. V. Bogdanova

    2014-01-01

    Full Text Available More than 8 million people in our country suffer from heart failure. About one million of these people die each year [1]. The problem of ventricular assist device creating - a mechanical device used for partial or complete replacement of heart function - is investigated for a long time (according to [2] just in our country since the 1970s. Today plenty of encouraging results are received. There is a number of VAD models which are successfully applied to patients with heart failure. After implantation, patients conduct a way of life that is normal in many respects: they are in the family, often they have an opportunity to work in their former specialty. Some of them live with the device about 8 years [3].According to [4] for 2010 the estimated total number of long-term devices implanted in the United States per year is over 1,700 (the population of the U.S. is 305 million, compared with over 430 per year in Europe (the population of Europe is 731 million. Unfortunately, people who need a heart transplant are much more.The principle of VAD is that being connected to the left ventricle with one cannula and to the ascending aorta with the other cannula the pump fully or partially replaces the function of the natural heart. This scheme allows the use of VAD in two ways: as a "bridge to transplantation" when the device is used temporarily until the donor heart is found, and a "bridge to recovery", when through the use of VAD the function of the heart muscle is recovered.VAD system can be divided into three subsystems: blood pump, power supply system and control system (Fig. 1.Each subsystem can be the subject of separate study. Special role in the development of VAD plays medical side of the issue. Successful research and development require interaction with qualified professionals in this field. The development of VAD is a multidisciplinary problem which demands fulfilment of a number of requirements.One of the most active programs in implantation of

  7. Design of wheel-type walking-assist device

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

    2006-03-15

    In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed.

  8. Current Treatment Strategies for Heart Failure: Role of Device Therapy and LV Reconstruction.

    Science.gov (United States)

    Janaswamy, Praneeth; Walters, Tomos E; Nazer, Babak; Lee, Randall J

    2016-09-01

    Medical care of heart failure (HF) begins with the determination of the cause of the heart failure and diagnosing potential reversible causes (i.e., coronary heart disease, hyperthyroidism, etc.). Medical therapy includes pharmacological and nonpharmacological strategies that limit and/or reverse the signs and symptoms of HF. Initial behavior modification includes dietary sodium and fluid restriction to avoid weight gain; and encouraging physical activity when appropriate. Optimization of medical therapy is the first line of treatment that includes the use of diuretics, vasodilators (i.e., ACE inhibitors or ARBs), beta blockers, and potentially inotropic agents and anticoagulation depending on the patient's severity of heart failure and LV dysfunction. As heart failure advances despite optimized medical management, cardiac resynchronization therapy (CRT), and implantable cardioverter defibrillators (ICDs) are appropriate device therapies. The development of progressive end-stage HF, despite maximal medical therapy, necessitates the consideration of mechanical circulatory devices such as ventricular assist devices (VADs) either as a bridge to heart transplantation or as destination therapy. Despite the advances in the treatment of heart failure, there is still a large morbidity and mortality associated with HF, thus the need to develop newer strategies for the treatment of HF.

  9. DuraHeart™ magnetically levitated left ventricular assist device: Osaka University experience.

    Science.gov (United States)

    Sakaguchi, Taichi; Matsumiya, Goro; Yoshioka, Daisuke; Miyagawa, Shigeru; Nishi, Hiroyuki; Yoshikawa, Yasushi; Fukushima, Satsuki; Saito, Shunsuke; Ueno, Takayoshi; Sawa, Yoshiki

    2013-01-01

    The DuraHeart left ventricular assist device (LVAD) is the world's first approved magnetically levitated implantable centrifugal pump. We report our initial experience with the DuraHeart as a bridge to heart transplantation. Between 2008 and 2011, 23 patients (17 males; mean age 35 years, range 16-53 years) with endstage heart failure underwent implantation with the DuraHeart LVAD at Osaka University Hospital. Of those, 7 underwent conversion surgery from a Nipro paracorporeal LVAD to the DuraHeart. There were no deaths during the mean support period of 559±241 days (176-999 days). In total, 17 patients (74%) remain with the LVAD and 5 (22%) underwent heart transplantation after 580±302 days (176-982 days) of support. Major adverse events included 8 (34%) driveline/pocket infections, 4 (17%) cerebrovascular accidents, 4 (17%) right heart failures requiring mechanical support, and 3 (13%) mechanical device failures (magnetic levitation failure caused by driveline fracture). Of the 5 patients who developed pump pocket infection, 3 underwent previous conversion surgery from the Nipro LVAD. Our initial experience with the DuraHeart LVAD in Japan demonstrated excellent long-term survival with acceptable rates of adverse events. With refinement of the system, including mechanical durability, this pump will further enhance the quality of life for patients who require long-term mechanical circulatory support.

  10. Device features for managing patients with heart failure.

    Science.gov (United States)

    Varma, Niraj; Wilkoff, Bruce

    2011-04-01

    Implanted devices in heart failure patients improve survival, but requires correct prescription, programming, and monitoring. Requirements change since heart failure is a dynamic condition. Repeated episodes of acute decompensation increase mortality. Events involve several processes converging to manifest with fluid congestion. Implantable devices identify changes such as those in rhythm, device function or hemodynamics. Incorporation of remote monitoring technology (TRUST Trial), enables tracking of these parameters and prompt notification of deviations, even if the patient remains asymptomatic. This may facilitate management of large patient volumes and enable pre-emptive treatment to improve outcomes in these high-risk patients.

  11. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    National Research Council Canada - National Science Library

    Liang, Fan; Yu, Yang; Wang, Haizhong; Meng, Xiaofeng

    2013-01-01

    Off-pump Coronary Artery Bypass Graft (CABG) surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools...

  12. Acoustic Characterization of Axial Flow Left Ventricular Assist Device Operation In Vitro and In Vivo.

    Science.gov (United States)

    Yost, Gardner L; Royston, Thomas J; Bhat, Geetha; Tatooles, Antone J

    2016-01-01

    The use of left ventricular assist devices (LVADs), implantable pumps used to supplement cardiac output, has become an increasingly common and effective treatment for advanced heart failure. Although modern continuous-flow LVADs improve quality of life and survival more than medical management of heart failure, device malfunction remains a common concern. Improved noninvasive methods for assessment of LVAD function are needed to detect device complications. An electronic stethoscope was used to record sounds from the HeartMate II axial flow pump in vitro and in vivo. The data were then uploaded to a computer and analyzed using two types of acoustic analysis software. Left ventricular assist device acoustics were quantified and were related to pump speed, acoustic environment, and inflow and outflow graft patency. Peak frequency values measured in vivo were found to correlate strongly with both predicted values and in vitro measurements (r > 0.999). Plots of the area under the acoustic spectrum curve, obtained by integrating over 50 Hz increments, showed strong correlations between in vivo and in vitro measurements (r > 0.966). Device thrombosis was found to be associated with reduced LVAD acoustic amplitude in two patients who underwent surgical device exchange.

  13. [Telemedicine and wireless devices in heart failure].

    Science.gov (United States)

    Billeci, Lucia; Guerriero, Lorenzo; L'Abbate, Antonio; Pioggia, Giovanni; Tartarisco, Gennaro; Trivella, Maria Giovanna

    2014-05-01

    Telemedicine has the potential to constitute the central element of the future primary care and become an effective means of prevention and early warning of acute exacerbation of chronic diseases. Up to now, the application of telemedicine has found a variety of difficulties, regarding the types and methods of acquisition and transmission of biological signals, the acceptance and cooperation of the patient, etc. The latest technological developments involve the combined use of wireless technologies and smartphones, for the collection and the transmission of data, and specific softwares for their automatic analysis. This paper examines some of the critical aspects in the application of new technologies for heart failure remote management.

  14. Transcatheter Interatrial Shunt Device for the Treatment of Heart Failure

    DEFF Research Database (Denmark)

    Feldman, Ted; Komtebedde, Jan; Burkhoff, Daniel

    2016-01-01

    UNLABELLED: Heart failure with preserved ejection fraction (HFpEF), a major public health problem with high morbidity and mortality rates, remains difficult to manage because of a lack of effective treatment options. Although HFpEF is a heterogeneous clinical syndrome, elevated left atrial pressure...... the rationale for a therapeutic transcatheter interatrial shunt device in HFpEF, and we describe the design of REDUCE Elevated Left Atrial Pressure in Heart Failure (REDUCE LAP-HF I), the first randomized controlled trial of a device-based therapy to reduce left atrial pressure in HFpEF. CLINICAL TRIAL...

  15. 34 CFR 300.5 - Assistive technology device.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Assistive technology device. 300.5 Section 300.5 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF...

  16. Investigation of hemodynamics in the assisted isolated porcine heart.

    Science.gov (United States)

    Granegger, Marcus; Mahr, Stephane; Horvat, Johann; Aigner, Philipp; Roehrich, Michael; Stoiber, Martin; Plasenzotti, Roberto; Zimpfer, Daniel; Schima, Heinrich; Moscato, Francesco

    2013-12-01

    Currently, the interaction between rotary blood pumps (RBP) and the heart is investigated in silico, in vitro, and in animal models. Isolated and defined changes in hemodynamic parameters are unattainable in animal models, while the heart-pump interaction in its whole complexity cannot be modeled in vitro or in silico. The aim of this work was to develop an isolated heart setup to provide a realistic heart-pump interface with the possibility of easily adjusting hemodynamic parameters. A mock circuit mimicking the systemic circulation was developed. Eight porcine hearts were harvested using a protocol similar to heart transplantation. Then, the hearts were resuscitated using Langendorff perfusion with rewarmed, oxygenated blood. An RBP was implanted and the setup was switched to the "working mode" with the left heart and the RBP working as under physiologic conditions. Both the unassisted and assisted hemodynamics were monitored. In the unassisted condition, cardiac output was up to 9.5 l/min and dP/dtmax ranged from 521 to 3621 mmHg/s at a preload of 15 mmHg and afterload of 70 mmHg. With the RBP turned on, hemodynamics similar to heart-failure patients were observed in each heart. Mean pump flow and flow pulsatility ranged from 0 to 11 l/min. We were able to reproduce conditions with an open and closed aortic valve as well as suction events. An isolated heart setup including an RBP was developed, which combines the advantages of in silico/vitro methods and animal experiments. This tool thus provides further insight into the interaction between the heart and an RBP.

  17. Design optimization of field-plate assisted RESURF devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Ferrara, A.; Heringa, A.; Steeneken, P.G.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

    2013-01-01

    A mathematical model for optimizing the 2-D potential distribution in the drift region of field-plate (FP)-assisted RESURF devices (Fig. 1) is presented. The proposed model extends earlier work [1-2] by including top-bottom dielectric asymmetry (typical in SOI devices [3]), non-zero field plate

  18. In Vitro Evaluation of Ventricular Cannulation for Rotodynamic Cardiac Assist Devices

    OpenAIRE

    Bachman, Timothy N.; Bahma, Jay K; Verkaik, Josiah; Vandenberghe, Stijn; Kormos, Robert L; James F Antaki

    2011-01-01

    The influence of positioning and geometry of ventricular cannulas for contemporary continuous flow Left Ventricular Assist Devices (LVADs) was evaluated in a non-beating isolated heart preparation with borescopic visualization. Preload and LVAD flow were varied to evaluate degrees of ventricular decompression up to the point of ventricular collapse. The performance of a flanged cannula was compared to a conventional bevel-tipped cannula: quantitatively by the maximal flow attainable, and qual...

  19. Modeling and control of a brushless DC axial flow ventricular assist device.

    Science.gov (United States)

    Giridharan, Guruprasad A; Skliar, Mikhail; Olsen, Donald B; Pantalos, George M

    2002-01-01

    This article presents an integrated model of the human circulatory system that incorporates circulatory support by a brushless DC axial flow ventricular assist device (VAD), and a feedback VAD controller designed to maintain physiologically sufficient perfusion. The developed integrated model combines a network type model of the circulatory system with a nonlinear dynamic model of the brushless DC pump We show that maintaining a reference differential pressure between the left ventricle and aorta leads to adequate perfusion for different pathologic cases, ranging from normal heart to left heart asystole, and widely varying physical activity scenarios from rest to exercise.

  20. VASCULAR INFLAMMATION AND ABNORMAL AORTIC HISTOMORPHOMETRY IN PATIENTS FOLLOWING PULSATILE AND CONTINUOUS FLOW LEFT VENTRICULAR ASSIST DEVICE PLACEMENT

    Science.gov (United States)

    Lee, Mike; Akashi, Hirokazu; Kato, Tomoko S.; Takayama, Hiroo; Wu, Christina; Xu, Katherine; Collado, Elias; Weber, Matthew P.; Kennel, Peter J.; Brunjes, Danielle L; Ji, Ruiping; Naka, Yoshifumi; George, Isaac; Mancini, Donna; Farr, Maryjane; Schulze, P. Christian

    2017-01-01

    Objective Left ventricular assist devices are increasingly used in patients with advanced heart failure as both destination therapy and bridge-to-transplantation. We aimed to analyze histomorphometric, structural and inflammatory changes following pulsatile and continuous flow left ventricular assist device placement. Method Clinical and echocardiographic data were collected from medical records. Aortic wall diameter, cellularity and inflammation were assessed by immunohistochemistry on aortic tissue collected at left ventricular assist device placement and at explantation during heart transplantation. Expression of adhesion molecules was quantified by western blot. Results Decellularization of the aortic tunica media was observed in patients receiving continuous flow support. Both device types showed an increased inflammatory response following left ventricular assist device placement with variable T cell and macrophage accumulations and increased expression of vascular E-selectin, ICAM and VCAM in the aortic wall. Conclusion Left ventricular assist device implantation is associated with distinct vascular derangements with development of vascular inflammation. These changes are pronounced in patients on continuous flow left ventricular assist and associated with aortic media decellularization. These findings help to explain the progressive aortic root dilation and vascular dysfunction in patients following continuous flow device placement. PMID:26899764

  1. A Numerical Simulation of HeartAssist5 Blood Pump Using an Advanced Turbulence Model.

    Science.gov (United States)

    Drešar, Primož; Rutten, Marcel C M; Gregorič, Igor D; Duhovnik, Jožef

    2017-10-23

    The need for mechanical assistance of the failing heart has increased with improvements in medicine and a rapidly aging population. In recent decades, significant progress has been made in the development and refinement of ventricular assist devices (VADs). Such devices operate in mixed laminar, transitional, and turbulent flow regime. One tool that assists in the development of VADs by facilitating understanding of the physical and mechanical properties of these flow regimes is computational fluid dynamics (CFD). In our investigation, we tested an advanced turbulence model that is a further development from standard Reynolds-averaged Navier-Stokes (RANS) models. From estimated pump flow rates (Q0) and constant rotation speed (n), pressure head (Δp) was calculated and validated with experimental data. An advanced turbulence model called scale adaptive simulation (SAS) was used in the solving of six different working cases comparing numerical SAS-SST and standard SST-kω models to experimental results.

  2. Hearing dogs - Assistive devices for the Deaf?

    OpenAIRE

    Záhorská, Kateřina

    2015-01-01

    This bachelor thesis deals with dogs employed in the socio-medical field, especially with assistance and hearing dogs. The thesis is divided into two parts, theoretical and practical. In the theoretical part the reader is introduced to the categories of dogs employed in this field, their special training (including interested organizations) is described and last but not least appropriate legislative measures are described. Attention is also paid to the situation abroad (in the USA, Great Brit...

  3. Ventricular assist device outflow graft in congenitally corrected transposition of great arteries - a surgical challenge

    Directory of Open Access Journals (Sweden)

    Mohite Prashant N

    2012-09-01

    Full Text Available Abstract Congenitally corrected transposition of the great arteries is a complex congenital cardiac anomaly with a wide spectrum of morphologic features and clinical profiles. Most patients are diagnosed late in their life, undergoes surgical repairs, eventually leading to systemic ventricular failure needing heart transplant or mechanical circulatory assistance. As, aorta is located anterior to and left of the PA (Transposition of great arteries, the outflow graft of ventricular assist device traverse across pulmonary artery to reach aorta which poses challenge during further surgical explorations.

  4. Human Grasp Assist Device With Exoskeleton

    Science.gov (United States)

    Bergelin, Bryan J (Inventor); Ihrke, Chris A. (Inventor); Davis, Donald R. (Inventor); Linn, Douglas Martin (Inventor); Bridgwater, Lyndon B. J. (Inventor)

    2014-01-01

    A grasp assist system includes a glove, actuator assembly, and controller. The glove includes a digit, i.e., a finger or thumb, and a force sensor. The sensor measures a grasping force applied to an object by an operator wearing the glove. Phalange rings are positioned with respect to the digit. A flexible tendon is connected at one end to one of the rings and is routed through the remaining rings. An exoskeleton positioned with respect to the digit includes hinged interconnecting members each connected to a corresponding ring, and/or a single piece of slotted material. The actuator assembly is connected to another end of the tendon. The controller calculates a tensile force in response to the measured grasping force, and commands the tensile force from the actuator assembly to thereby pull on the tendon. The exoskeleton offloads some of the tensile force from the operator's finger to the glove.

  5. What to Expect After Heart Surgery

    Science.gov (United States)

    ... patients. Surgery To Place Ventricular Assist Devices or Total Artificial Hearts A VAD is a mechanical pump that is ... Implantable Cardioverter Defibrillators Pacemakers Percutaneous Coronary Intervention Stents Total Artificial Heart Ventricular Assist Device Other Resources NHLBI Resources "Your ...

  6. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-01-01

    Full Text Available Off-pump Coronary Artery Bypass Graft (CABG surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track control procedures. It is technically preferable to model heart motion in a nonlinear way because the characteristic analysis of 3D heart motion data through Bi-spectral analysis and Fourier methods demonstrates the involved nonlinearity of heart motion. We propose an adaptive nonlinear heart motion model based on the Volterra Series in this paper. We also design a fast lattice structure to achieve computational-efficiency for real-time online predictions. We argue that the quadratic term of the Volterra Series can improve the prediction accuracy by covering sharp change points and including the motion with sufficient detail. The experiment results indicate that the adaptive nonlinear heart motion prediction algorithm outperforms the autoregressive (AR and the time-varying Fourier-series models in terms of the root mean square of the prediction error and the prediction error in extreme cases.

  7. Clinical outcomes after implantation of a centrifugal flow left ventricular assist device and concurrent cardiac valve procedures.

    Science.gov (United States)

    Milano, Carmelo; Pagani, Francis D; Slaughter, Mark S; Pham, Duc Thinh; Hathaway, David R; Jacoski, Mary V; Najarian, Kevin B; Aaronson, Keith D

    2014-09-09

    Cardiac valve procedures are commonly performed concurrently during implantation of left ventricular assist devices, but the added procedural risk has not been studied in detail. Data from patients receiving the HeartWare Ventricular Assist Device in the ADVANCE bridge to transplant (BTT) trial and continued access protocol were reviewed. Of 382 consecutive patients who completed follow-up between August 2008 and June 2013 (mean time on support 389 days, median 271 days), 262 (68.6%) underwent isolated HeartWare Ventricular Assist Device implantation, 75 (19.6%) a concurrent valve procedure, and 45 (11.8%) concurrent nonvalvular procedures. Of the concurrent valve procedures, 56 were tricuspid, 13 aortic, and 6 mitral. Survival was similar between groups (79% for concurrent valve procedures and 85% for HeartWare Ventricular Assist Device only at 1 year; P=0.33). Concurrent valve procedures were also associated with increased unadjusted early right heart failure (RHF). A multivariable analysis for death and RHF (121 total events) identified female sex (odds ratio=2.0 [95% confidence interval, 1.2-3.3; P=0.0053]) and preimplant tricuspid regurgitation severity (odds ratio=2.9 [95% confidence interval, 1.8-4.8, PRHF compared with those who received TVP (0.19 versus 0.05 events per patient-year, respectively; P=0.024). Compared with HeartWare Ventricular Assist Device alone, survival was equivalent for the concurrent valve procedure group. Tricuspid regurgitation severity was the most important predictor of increased postoperative RHF, and concurrent TVP was not an independent predictor of RHF overall. Concurrent TVP may reduce the rate of late RHF for patients with significant preimplant tricuspid insufficiency. http://www.clinicaltrials.gov. Unique identifier: NCT00751972. © 2014 American Heart Association, Inc.

  8. Users’ Satisfaction with Assistive Devices in South Korea

    OpenAIRE

    Lee, Sang-Heon

    2014-01-01

    [Purpose] The objective of this study was to determine users’ satisfaction with assistive devices, and their serviceability and effectiveness. [Methods] A random sample of 138 users participated in this study. The Korean-Quebec User Evaluation of Satisfaction with Assistive Technology 2.0 and an additional questionnaire were used for data collection. Data were analyzed by using descriptive statistics. [Results] Overall client satisfaction was high. Respondents most commonly reported use of th...

  9. A mock heart engineered with helical aramid fibers for in vitro cardiovascular device testing.

    Science.gov (United States)

    Jansen-Park, So-Hyun; Hsu, Po-Lin; Müller, Indra; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas

    2017-04-01

    Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters. Ventricle and aorta molds were produced based on MRI data and cast with silicone. Aramid fibers were layered in the silicone ventricle to reproduce ventricle torsion. A rotating hollow shaft was connected to the apex enabling the rotation of the MH and the connection of a VAD. Silicone wall thickness, aramid fiber angle and fiber pitch were varied to generate different MH models. All MH models were placed in a tank filled with variable amounts of water and air simulating the compliance. In this work, physiological ventricular torsion angles (15°-26°) and physiological pressure-volume loops were achieved. This MHCL can serve as a comprehensive testing platform for cardiovascular devices, such as artificial heart valves and cannulation of VADs.

  10. Update on device technologies for monitoring heart failure.

    Science.gov (United States)

    Singh, Bharat; Russell, Stuart D; Cheng, Alan

    2012-10-01

    Congestive heart failure (CHF) affects more than 5 million people in the United States and is one of the most common reasons for recurrent hospitalizations. Since the majority of admissions related to CHF are secondary to progressively worsening congestion, many clinicians are quick to initiate aggressive diuresis once early signs of impending heart failure develop. These signs are based in large measure on patient-reported symptoms. Unfortunately, recent trials have shown that traditional ambulatory monitoring of heart failure using patient symptoms or body weight do not reduce episodes of decompensated heart failure requiring hospitalization. This has led to great interest in developing monitoring systems that can detect impending episodes of CHF even prior to the development of symptoms. Some of the these systems utilize existing implantable cardioverter defibrillators and cardiac resynchronization therapy devices to monitor electrophysiologic parameters including the presence of ventricular arrhythmias, heart rate variability and even transthoracic impedances. Other more recent developments have focused on more invasive hemodynamic monitoring systems that can measure pressures in the right ventricle, pulmonary arteries and the left atrium. The data on the utility of such systems is limited but encouraging. While none of these systems are currently FDA approved, they have been applied in a number of clinical trials. This paper highlights the currently available monitoring systems for heart failure and reviews the evidence supporting its use.

  11. Effects of Left Ventricular Assist Device Support on End-Organ Function in Patients With Heart Failure: Comparison of Pulsatile- and Continuous-Flow Support in a Single-Center Experience.

    Science.gov (United States)

    Nadziakiewicz, P; Szygula-Jurkiewicz, B; Niklewski, T; Pacholewicz, J; Zakliczynski, M; Borkowski, J; Hrapkowicz, T; Zembala, M

    2016-06-01

    Limited data exist about the effects of continuous-flow versus pulsatile-flow left ventricular assist devices (LVADs) on end-organ function. We hypothesized that a pulsatile Polvad MEV (PM) would result in outcomes similar to those of similarly ill patients implanted with a continuous-flow LVAD (Heartware [HW] or Heartmate II [HMII]). We aimed to compare renal, hepatic, and hematologic functions in the 1st 30 days of support. We retrospectively reviewed patients with 24 PM (21 M, 3 F; group P) and 15 HW and 5 HMII (20 M, 0 F); group C LVAD implantations from April 2007 to February 2014. Creatinine, bilirubin, aspartate (AST) and alanine (ALT) transaminases, hematocrit, platelet count, international normalized ratio (INR), and activated partial thromboplastin time (APTT) parameters were analyzed before implantation and during 30 days of support. Demographic parameters were similar. No significant differences were found between the groups regarding baseline renal, hepatic, or hematologic function. Baseline INR and APTT were significantly higher in group P. Levels of creatinine were similar between groups. They increased from baseline to postoperative day (POD) 1 and then decreased. Bilirubin levels were insignificantly higher in group P. Transaminases were significantly higher in group P (AST in PODs 3-6, ALT in PODs 3-7). INR values were significantly higher at baseline and in POD 0. APTT values were insignificantly higher in group P. The use of LVAD improved renal and hepatic function in our series. Patients in group P had more decreased hepatic function and presented slower regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. A Quadratic Nonlinear Prediction-Based Heart Motion Model Following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    OpenAIRE

    Fan Liang; Xiaofeng Meng

    2013-01-01

    Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic tools, which reduces post-surgery complications for patients. The challenge for the robot assisted tool when tracking the beating heart is the abrupt change caused by the nonlinear nature of heart motion and high precision surgery requirements. A characteristic analysis of 3D heart motion data thro...

  13. Pump flow estimation from pressure head and power uptake for the HeartAssist5, HeartMate II, and HeartWare VADs.

    Science.gov (United States)

    Pennings, Kim A M A; Martina, Jerson R; Rodermans, Ben F M; Lahpor, Jaap R; van de Vosse, Frans N; de Mol, Bas A J M; Rutten, Marcel C M

    2013-01-01

    The use of long-term mechanical circulatory support (MCS) for heart failure by means of implanted continuous-flow left ventricular assist devices (cf-LVADs) will increase, either to enable recovery or to provide a destination therapy. The effectiveness and user-friendliness of MCS will depend on the development of near-physiologic control strategies for which accurate estimation of pump flow is essential. To provide means for the assessment of pump flow, this study presents pump models, estimating pump flow (Q(lvad)) from pump speed (n) and pressure difference across the LVAD (Δp(lvad)) or power uptake (P). The models are evaluated for the axial-flow LVADs HeartAssist5 (HA5) and HeartMate II (HMII), and for a centrifugal pump, the HeartWare (HW). For all three pumps, models estimating Q(lvad) from Δp(lvad) only is capable of describing pump behavior under static conditions. For the axial pumps, flow estimation from power uptake alone was not accurate. When assuming an increase in pump flow with increasing power uptake, low pump flows are overestimated in these pumps. Only for the HW, pump flow increased linearly with power uptake, resulting in a power-based pump model that estimates static pump flow accurately. The addition of pressure head measurements improved accuracy in the axial cf-LVAD estimation models.

  14. Sheath hemorrhage after percutaneous ventricular assist device implantation.

    Science.gov (United States)

    Siddiqi, Saadi; Ganga, Harsha V; Dhesi, Pavittarpaul; Azemi, Talhat; Chamakura, Sanjayant; Kiernan, Francis J; Hammond, Jonathan A; Sadiq, Immad R

    2014-04-01

    Technical advances in temporary ventricular assist devices (VADs) continue to progress, allowing for percutaneous implantation during times of hemodynamic instability. However, device delivery systems, i.e., sheaths, lag in their ability to sustain the mechanical demands of these VADs for extended periods. We propose both a novel technique and the implementation of an emergency preparedness plan to be enacted specifically during those times when delivery systems fail thereby leading to potentially catastrophic bleeding complications.

  15. Exercise hemodynamics during extended continuous flow left ventricular assist device support: the response of systemic cardiovascular parameters and pump performance

    NARCIS (Netherlands)

    Martina, Jerson; Jonge, Nicolaas; Rutten, Marcel; Kirkels, J. Hans; Klöpping, Corinne; Rodermans, Ben; Sukkel, Eveline; Hulstein, Nelienke; Mol, Bas; Lahpor, Jaap

    2013-01-01

    Patients on continuous flow left ventricular assist devices (cf-LVADs) are able to return to an active lifestyle and perform all sorts of physical activities. This study aims to evaluate exercise hemodynamics in patients with a HeartMate II cf-LVAD (HM II). Thirty (30) patients underwent a bicycle

  16. Impact of Obesity on Readmission in Patients With Left Ventricular Assist Devices.

    Science.gov (United States)

    Han, Jiho; Mauro, Christine M; Kurlansky, Paul A; Fukuhara, Shinichi; Yuzefpolskaya, Melana; Topkara, Veli K; Garan, A Reshad; Colombo, Paolo C; Takayama, Hiroo; Naka, Yoshifumi; Takeda, Koji

    2018-02-01

    Hospital readmissions have an adverse effect on the quality of life in patients with end-stage heart failure. We examined the temporal pattern, predictors, and outcomes of readmission in continuous flow left ventricular assist device-supported patients. We retrospectively reviewed inpatient data of 350 consecutive patients who received a continuous-flow left ventricular assist device at our center between May 2004 and December 2014. A total time-restricted model was used to estimate hazard ratios for readmission, and the Nelson nonparametric method was used to estimate mean cumulative function for each cause of readmission. The mean age was 57 ± 13 years, 82.6% received a HeartMate II (Abbott Laboratories, Chicago, IL), and 26.3% were destination therapy. The 30-day readmission rate was 21.7%, and 264 readmissions (41.1%) occurred within the first 6 months of support. The leading cause of readmission was bleeding (0.74 mean cumulative events per person), followed by infection (0.7), device failure (0.52), arrhythmia (0.3), and right heart failure (0.28) at 3 years. The number of readmissions did not have an adverse effect on survival (hazard ratio, 1.03; 95% confidence interval, 0.92 to 1.17; p = 0.58). Increase in each body mass index unit was associated with 1.029 times the rate of overall readmission (p = 0.041). Patients with a body mass index of 30 kg/m2 or higher had increased readmissions for device failure (p = 0.008) and right heart failure (p = 0.03). Readmission burden is highest during the first few months of continuous-flow left ventricular assist device support, but survival is not affected. Patients with an elevated body mass index are at increased risk for readmissions for device failure and right heart failure. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Physical Therapy for a Child Poststroke With a Left Ventricular Assist Device.

    Science.gov (United States)

    Lombard, Kelly A

    2016-01-01

    To describe physical therapy (PT) examination and intervention during rehabilitation for a child poststroke with an implanted left ventricular assist device (LVAD). A 10-year-old boy with a history of congenital heart disease awaiting heart transplant was admitted to a pediatric rehabilitation hospital with right hemiplegia, and an external, portable LVAD. This child participated in standard PT examination procedures and interventions with accommodations for the LVAD. Observation was used to evaluate exercise response because of inability to measure vital signs. At admission, impaired muscle tone, balance, and endurance contributed to limitations in functional mobility. By discharge, improvements were seen in all impairments and also in ambulation distance, speed, and independence. This child awaiting heart transplant with an LVAD was able to tolerate intensive individualized PT. With monitoring and adjustments to the plan of care, he demonstrated improvements in functional mobility.

  18. Laser-assisted manufacturing of thermal energy devices

    Science.gov (United States)

    Zhang, Tao; Tewolde, Mahder; Kim, Ki-Hoon; Seo, Dong-Min; Longtin, Jon P.; Hwang, David J.

    2016-03-01

    In this study, we will present recent progress in the laser-assisted manufacturing of thermal energy devices that require suppressed thermal transport characteristics yet maintaining other functionalities such as electronic transport or mechanical strength. Examples of such devices to be demonstrated include thermoelectric generator or insulating materials. To this end, it will be shown that an additive manufacturing approaches can be facilitated and improved by unique processing capabilities of lasers in composite level. In order to tailor thermal characteristics in thermal devices, we will mainly investigate the potential of laser heating, curing, selective removal and sintering processes of material systems in the composite level.

  19. VENTRICLE ASSIST DEVICE: PAST, PRESENT, AND FUTURE NONPULSATILE PUMPS

    Directory of Open Access Journals (Sweden)

    G. Р. Itkin

    2009-01-01

    Full Text Available The article briefly describes the history of the non-pulsating type blood pumps for ventricular assist circulation and heart-lung machine. Disclosed the main advantages of these pumps before pulsating type, especially for implantable systems development. However, disadvantages of these pumps and the directions of minimize or eliminate ones have shown. Specific examples of our implantable centrifugal and axial pump developments are presented. Declare the ways to further improve the pumps. 

  20. Single Versus Multidrug Regimen for Surgical Infection Prophylaxis in Left Ventricular Assist Device Implantation.

    Science.gov (United States)

    Aburjania, Nana; Ertmer, Brennan M; Farid, Saira; Berg, Melody; Nienaber, Juhsien J C; Tchantchaleishvili, Vakhtang; Stulak, John M; Sohail, Muhammad R

    2017-10-31

    Infection is a serious complication of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen for LVAD implantation is not well established. We retrospectively reviewed all adults who underwent continuous-flow LVAD implantation from February 2007 to March 2015 at Mayo Clinic Rochester. Left ventricular assist device infection (LVADI) was defined using criteria published by the International Society for Heart and Lung Transplant. Patients excluded from the analysis included those who did not have HeartMate II or HeartWare device, patients with incomplete documentation of SIP, and those with an actively treated infection at the time of LVAD implantation. We compared risk of LVAD-specific and LVAD-related infections and all-cause mortality between SIP regimens at postoperative day 90 and 1 year using Kaplan-Meier time-to-event analyses. During study period, 239 adults underwent continuous-flow LVAD implantation at our institution where 199 patients received single-drug and 40 received multidrug SIP regimen. Median patient age was 62 years. Left ventricular assist device infection occurred in three patients (1.5%) in the single-drug group versus two patients (5.0%) in the multidrug group at 90 days (p = 0.4). There was no difference in infection-free (p = 0.4) and overall survival (p = 0.9) between two groups at 1 year. In conclusion, there was no clear benefit of using multidrug regimen as it did not impact infection-free survival or all-cause mortality compared with single-drug regimen. Prospective clinical trials are needed to further define the optimal SIP regimen for LVAD implantation.

  1. Surgical energy device using steam jet for robotic assisted surgery.

    Science.gov (United States)

    Yoshiki, Hitoshi; Tadano, Kotaro; Ban, Daisuke; Ohuchi, Katsuhiro; Tanabe, Minoru; Kawashima, Kenji

    2015-01-01

    In robotic assisted surgery, the carbonization and the adherence of coagulated tissues caused by surgical energy devices are problems. We propose a surgical energy device using a steam jet to solve the problems. The device applies a steam jet and performs coagulation and hemostasis. The exposed tissue is heated quickly with latent heat of the steam. The carbonization and the adherence of the tissue can be avoided. We prototyped a steam jet coagulator to prove the concept. The coagulator was mounted on the laparoscopic surgical robot. The effectiveness of the coagulation and hemostasis using steam was confirmed by the in vitro experiment on the chicken's liver and the in vivo experiments on the pig's spleen under the robotic assisted laparoscopic environment.

  2. High reliability linear drive device for artificial hearts

    Science.gov (United States)

    Ji, Jinghua; Zhao, Wenxiang; Liu, Guohai; Shen, Yue; Wang, Fangqun

    2012-04-01

    In this paper, a new high reliability linear drive device, termed as stator-permanent-magnet tubular oscillating actuator (SPM-TOA), is proposed for artificial hearts (AHs). The key is to incorporate the concept of two independent phases into this linear AH device, hence achieving high reliability operation. The fault-tolerant teeth are employed to provide the desired decoupling phases in magnetic circuit. Also, as the magnets and the coils are located in the stator, the proposed SPM-TOA takes the definite advantages of robust mover and direct-drive capability. By using the time-stepping finite element method, the electromagnetic characteristics of the proposed SPM-TOA are analyzed, including magnetic field distributions, flux linkages, back- electromotive forces (back-EMFs) self- and mutual inductances, as well as cogging and thrust forces. The results confirm that the proposed SPM-TOA meets the dimension, weight, and force requirements of the AH drive device.

  3. Fluoroscopy-Guided Resolution of Ingested Thrombus Leading to Functional Disturbance of a Continuous-Flow Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Jens Garbade

    2012-01-01

    Full Text Available The third generation of left ventricular assist devices (LVADs has been shown to improve outcome and quality of life in patients suffering from acute and chronic heart failure. However, VAD-associated complications are still a challenge in the clinical practice. Here we report the resolution of a mobile thrombus formation in the proximity of the inflow cannula of a third generation of LVADs (HVAD Pump, HeartWare, Inc. in a patient with chronic heart failure 4 months after implantation.

  4. Quantifying the effect of cardiorenal syndrome on mortality after left ventricular assist device implant.

    Science.gov (United States)

    Kirklin, James K; Naftel, David C; Kormos, Robert L; Pagani, Francis D; Myers, Susan L; Stevenson, Lynne W; Givertz, Michael M; Young, James B

    2013-12-01

    Comorbidities complicate recovery and contribute to mortality after implant of a left ventricular assist device (LVAD). Coexistent cardiac and renal dysfunction (so-called cardiorenal syndrome) increases the risk of death, both with advanced heart failure and after LVAD implantation. We analyzed patients from the Interagency Registry for Mechanically Assist Circulatory Support to better estimate postimplant mortality according to the severity of renal dysfunction. Patients with a continuous-flow LVAD were grouped according to their pre-implant level of renal dysfunction: severe was defined as dialysis and/or estimated glomerular filtration rate (eGFR) 60 mg/dl; and mild or no renal dysfunction if eGFR was ≥ 60 ml/min and BUN was cardiorenal syndrome is advanced. For patients with severe renal dysfunction and other major comorbidities, initial support with a temporary device while awaiting organ recovery before implanting a durable pump could be considered. © 2013 International Society for Heart and Lung Transplantation Published by International Society for the Heart and Lung Transplantation All rights reserved.

  5. A novel design of ventricular assist device: an in vitro feasibility study.

    Science.gov (United States)

    Boccaccio, Antonio; Carbone, Carmine; Galietti, Umberto; Mastropasqua, Filippo; Pappalettere, Carmine

    2012-11-01

    Left ventricular assist devices (LVADs) work as a bypass between the left ventricular apex and the ascending aorta. The surgical procedure for their insertion requires the opening of the cardiac cavities and the dissection of the great vessels, the blood is constrained to flow through the device components and the risk can be run of thrombogenesis, haemolysis and infections. A possible strategy to overcome this limitation consists in utilizing external systems that assist the heart in its contraction from the outside without directly transporting the blood. In this study we conduct the feasibility analysis of a novel external LVAD design that does not require the opening of the cardiac cavities and the dissection of the great vessels and that allows the removal procedure to be easily achieved. The device, including a stepper motor, three metallic wires and three elastic elements, works alternatively between a contraction condition where it induces an elastic compulsion on the heart and a release condition where it elastically releases the organ. The values of force acting on the wires and the values of current supplied to the motor were measured and utilized for a preliminary study design. The experimental measurements demonstrated the feasibility of the system.

  6. Remote management of heart failure using implantable electronic devices.

    Science.gov (United States)

    Morgan, John M; Kitt, Sue; Gill, Jas; McComb, Janet M; Ng, Ghulam Andre; Raftery, James; Roderick, Paul; Seed, Alison; Williams, Simon G; Witte, Klaus K; Wright, David Jay; Harris, Scott; Cowie, Martin R

    2017-08-07

    Remote management of heart failure using implantable electronic devices (REM-HF) aimed to assess the clinical and cost-effectiveness of remote monitoring (RM) of heart failure in patients with cardiac implanted electronic devices (CIEDs). Between 29 September 2011 and 31 March 2014, we randomly assigned 1650 patients with heart failure and a CIED to active RM or usual care (UC). The active RM pathway included formalized remote follow-up protocols, and UC was standard practice in nine recruiting centres in England. The primary endpoint in the time to event analysis was the 1st event of death from any cause or unplanned hospitalization for cardiovascular reasons. Secondary endpoints included death from any cause, death from cardiovascular reasons, death from cardiovascular reasons and unplanned cardiovascular hospitalization, unplanned cardiovascular hospitalization, and unplanned hospitalization. REM-HF is registered with ISRCTN (96536028). The mean age of the population was 70 years (range 23-98); 86% were male. Patients were followed for a median of 2.8 years (range 0-4.3 years) completing on 31 January 2016. Patient adherence was high with a drop out of 4.3% over the course of the study. The incidence of the primary endpoint did not differ significantly between active RM and UC groups, which occurred in 42.4 and 40.8% of patients, respectively [hazard ratio 1.01; 95% confidence interval (CI) 0.87-1.18; P = 0.87]. There were no significant differences between the two groups with respect to any of the secondary endpoints or the time to the primary endpoint components. Among patients with heart failure and a CIED, RM using weekly downloads and a formalized follow up approach does not improve outcomes.

  7. Safety and Feasibility of Laparoscopic Abdominal Surgery in Patients With Mechanical Circulatory Assist Devices.

    Science.gov (United States)

    Ashfaq, Awais; Chapital, Alyssa B; Johnson, Daniel J; Staley, Linda L; Arabia, Francisco A; Harold, Kristi L

    2016-10-01

    Objectives Increasing number of mechanical circulatory assist devices (MCADs) are being placed in heart failure patients. Morbidity from device placement is high and the outcome of patients who require noncardiac surgery after, is unclear. As laparoscopic interventions are associated with decreased morbidity, we examined the impact of such procedures in these patients. Methods A retrospective review was conducted on 302 patients who underwent MCAD placement from 2005 to 2012. All laparoscopic abdominal surgeries were included and impact on postoperative morbidity and mortality studied. Results Ten out of 16 procedures were laparoscopic with 1 conversion to open. Seven patients had a HeartMate II, 2 had Total Artificial Hearts, and 1 had CentriMag. Four patients had devices for ischemic cardiomyopathy and 6 cases were emergent. Surgeries included 6 laparoscopic cholecystectomies, 2 exploratory laparoscopies, 1 laparoscopic colostomy takedown, and 1 laparoscopic ventral hernia repair with mesh. Median age of the patients was 63 years (range, 29-79 years). Median operative time was 123 minutes (range, 30-380 minutes). Five of 10 patients were on preoperative anticoagulation with average intraoperative blood loss of 150 mL (range, 20-700 mL). There were 3 postoperative complications; acute respiratory failure, acute kidney injury and multisystem organ failure resulting in death not related to the surgical procedure. Conclusion The need for noncardiac surgery in post-MCAD patients is increasing due to limited donors and due to more durable and longer support from newer generation assist devices. While surgery should be approached with caution in this high-risk group, laparoscopic surgery appears to be a safe and successful treatment option. © The Author(s) 2016.

  8. Monitoring mobility assistive device use in post-stroke patients

    DEFF Research Database (Denmark)

    Boissy, Patrice; Hester, Todd; Sherrill, Delsey

    2007-01-01

    Mobility assistive devices (MAD) such as canes can improve mobility and allow independence in the performance of mobility-related tasks. The use of MAD is often prescribed for stroke survivors. Despite their acknowledged qualities, MAD in real life conditions are typically underutilized, misused ...... accelerometers, gyroscopes, and a load cell to identify the task a patient was performing and examine the use of the cane in the context of the task....

  9. Assistive Device For Visually Impaired People By Using Ultrasonic Sensors

    Directory of Open Access Journals (Sweden)

    Hninn Nandar Aye

    2015-08-01

    Full Text Available The visually impaired people need some aid to walk and move safety in their surroundings. The ordinary people cannot know how hard it is to live and move in daily life for the blindness the visually impaired people and the old person who has poor vision. Although the sighted people cannot help the blindness to regain the eyesight the visually impaired one can try to make easier the daily routine by using the assistive device that can detect the obstacles near the blindness and the visually impaired people and warn the alert to the users before accidence. This assistive device like walking stick contains ultrasonic sensors PIC microcontroller Peripheral Interface Controller LDR vibrator servo motor buzzer and LED. Ultrasonic sensors are used for sensing and detecting the obstacles near the user to avoid the dangerous condition. Vibrator and buzzer are used for providing the alert to know that the obstacle is near. Servo motor is used for turning the wheel easily without effort. LDR and LED is used for lighting in low light room and at night to know the ordinary or sighted people where the walking stick is so this assistive device will be safe from the other peoples hit.

  10. Anesthesia for gastrointestinal endoscopy in patients with left ventricular assist devices: Initial experience with 68 procedures

    Directory of Open Access Journals (Sweden)

    Basavana G Goudra

    2013-01-01

    Full Text Available Aims and Objectives: Continuous flow left ventricular assist devices (LVAD have emerged as a reliable treatment option for heart failure. Because of bleeding secondary to anticoagulation, these patients present frequently for gastrointestinal (GI endoscopy. The presently available literature on perioperative management of these patients is extremely limited and is primarily based upon theoretical principles. Materials and Methods: Perioperative records of patients with LVAD undergoing (GI endoscopy between 2008 and 2012 were reviewed. Patient, device and procedure specific information was analyzed. Results: A total of 105 LVADs were implanted, and 68 procedures were performed in 39 patients. The most common indication was GI bleed (48/68, with yearly risk of 8.57% per patient. A total of 63 procedures were performed under deep sedation, with five procedures requiring general anesthesia. Intra-procedure hypotension was managed by fluids and (or vasopressors/inotropes (phenylephrine, ephedrine or milrinone guided by plethysmographic waveform, non-invasive blood pressure (NIBP and LVADs pulsatility index (for HeartMate II/flow pulsatility (for HeartWare. No patient required invasive monitoring and both NIBP and pulse oximeter could be reliably used for monitoring (and guided management in all patients due to the presence of native heart′s pulsatile output. Conclusion: In the presence of residual heart function, with optimal device settings, non-invasive hemodynamic monitoring can be reliably used in these patients while undergoing GI endoscopy under general anesthesia or monitored anesthesia care. Transient hypotensive episodes respond well to fluids/vasopressors without the need of increasing device speed that can be detrimental.

  11. Development and assessment of a hand assist device: GRIPIT.

    Science.gov (United States)

    Kim, Byungchul; In, Hyunki; Lee, Dae-Young; Cho, Kyu-Jin

    2017-02-21

    Although various hand assist devices have been commercialized for people with paralysis, they are somewhat limited in terms of tool fixation and device attachment method. Hand exoskeleton robots allow users to grasp a wider range of tools but are heavy, complicated, and bulky owing to the presence of numerous actuators and controllers. The GRIPIT hand assist device overcomes the limitations of both conventional devices and exoskeleton robots by providing improved tool fixation and device attachment in a lightweight and compact device. GRIPIT has been designed to assist tripod grasp for people with spinal cord injury because this grasp posture is frequently used in school and offices for such activities as writing and grasping small objects. The main development objective of GRIPIT is to assist users to grasp tools with their own hand using a lightweight, compact assistive device that is manually operated via a single wire. GRIPIT consists of only a glove, a wire, and a small structure that maintains tendon tension to permit a stable grasp. The tendon routing points are designed to apply force to the thumb, index finger, and middle finger to form a tripod grasp. A tension-maintenance structure sustains the grasp posture with appropriate tension. Following device development, four people with spinal cord injury were recruited to verify the writing performance of GRIPIT compared to the performance of a conventional penholder and handwriting. Writing was chosen as the assessment task because it requires a tripod grasp, which is one of the main performance objectives of GRIPIT. New assessment, which includes six different writing tasks, was devised to measure writing ability from various viewpoints including both qualitative and quantitative methods, while most conventional assessments include only qualitative methods or simple time measuring assessments. Appearance, portability, difficulty of wearing, difficulty of grasping the subject, writing sensation, fatigability

  12. Advanced patient transfer assist device with intuitive interaction control.

    Science.gov (United States)

    Humphreys, Heather C; Choi, Young Mi; Book, Wayne J

    2017-10-24

    This research aims to improve patient transfers by developing a new type of advanced robotic assist device. It has multiple actuated degrees of freedom and a powered steerable base to maximize maneuverability around obstacles. An intuitive interface and control strategy allows the caregiver to simply push on the machine in the direction of desired patient motion. The control integrates measurements of both force and proximity to mitigate any potential large collision forces and provides operators information about obstacles with a form of haptic feedback. Electro-hydraulic pump controlled actuation provides high force density for the actuation. Nineteen participants performed tests to compare transfer operations (transferring a 250-lb mannequin between a wheelchair, chair, bed, and floor) and interaction control of a prototype device with a commercially available patient lift. The testing included a time study of the transfer operations and subjective rating of device performance. The results show that operators perform transfer tasks significantly faster and rate performance higher using the prototype patient transfer assist device than with a current market patient lift. With further development, features of the new patient lift can help facilitate patient transfers that are safer, easier, and more efficient for caregivers.

  13. Hemodynamic Performance of a Novel Right Ventricular Assist Device (PERKAT)

    Science.gov (United States)

    Schulze, P. Christian; Ferrari, Markus W.

    2017-01-01

    Acute right ventricular failure (RVF) is an increasing clinical problem and a life-threatening condition. Right ventricular assist devices represent a reasonable treatment option for patients with refractory RVF. We here present a novel percutaneously implantable device for right ventricular support. The PERKAT device is based on a nitinol stent cage, which is covered with valve-carrying foils. A flexible outlet trunk with a pigtail tip is connected to the distal part. The device is driven by an intra-aortic balloon pump (IABP) drive unit, which inflates/deflates a standard IABP-balloon placed within the stent cage. In-vitro evaluation was done in a liquid bath containing water or blood analog. The PERKAT device was tested in different afterload settings using two different IABP-balloons and varying inflation/deflation rates. We detected flow rates ranging from 1.97 to 3.93 L/min depending on the afterload setting, inflation/deflation rate, balloon size, and the medium used. Flow rates between water and blood analog were nearly comparable, and in the higher inflation/deflation rate settings slightly higher with water. Based on this promising in vitro data, the innovative percutaneously implantable PERKAT device has a potential to become a therapeutic option for patients with RVF refractory to medical treatment. PMID:27831998

  14. Network-Assisted Device-to-Device (D2D) Direct Proximity Discovery with Underlay Communication

    DEFF Research Database (Denmark)

    Pratas, Nuno; Popovski, Petar

    2015-01-01

    Device-to-Device communications are expected to play an important role in current and future cellular generations, by increasing the spatial reuse of spectrum resources and enabling lower latency communication links. This paradigm has two fundamental building blocks: (i) proximity discovery and (ii......) direct communication between proximate devices. While (ii) is treated extensively in the recent literature, (i) has received relatively little attention. In this paper we analyze a network-assisted underlay proximity discovery protocol, where a cellular device can take the role of: announcer (which......, we consider the case where the announcers underlay their messages in the downlink transmissions that are directed towards the monitoring devices. We propose a power control scheme applied to the downlink transmission, which copes with the underlay transmission via additional power expenditure, while...

  15. Partial Nephrectomy in a Patient with a Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Jules P. Manger

    2011-01-01

    Full Text Available Left ventricular assist device (LVAD use has increased as a bridge to heart transplant as well as destination therapy in patients with severe heart failure. Presence of LVAD is not a contraindication to noncardiac surgery but does present special challenges to the surgical, anesthesia, and cardiac teams. We present the case of a 40-year-old woman with idiopathic cardiomyopathy necessitating LVAD who underwent left partial nephrectomy for a renal mass. She had undergone three nondiagnostic percutaneous image-guided biopsies. Left partial nephrectomy was performed. Perioperative care was without incident due to careful oversight by a multidisciplinary team. Pathology revealed high-grade clear cell renal cell carcinoma (RCC with negative margins. Polytetrafluoroethylene (PTFE bolsters were misidentified six months postoperatively on computed tomography (CT at an outside institution as a retained laparotomy sponge. This is, to our knowledge, the first report of a partial nephrectomy performed in a patient with LVAD.

  16. Activity Recognition in Individuals Walking With Assistive Devices: The Benefits of Device-Specific Models

    Science.gov (United States)

    Gupta, Aakash; Deems-Dluhy, Susan; Hoppe-Ludwig, Shenan; Kording, Konrad; Jayaraman, Arun

    2017-01-01

    Background Wearable sensors gather data that machine-learning models can convert into an identification of physical activities, a clinically relevant outcome measure. However, when individuals with disabilities upgrade to a new walking assistive device, their gait patterns can change, which could affect the accuracy of activity recognition. Objective The objective of this study was to assess whether we need to train an activity recognition model with labeled data from activities performed with the new assistive device, rather than data from the original device or from healthy individuals. Methods Data were collected from 11 healthy controls as well as from 11 age-matched individuals with disabilities who used a standard stance control knee-ankle-foot orthosis (KAFO), and then a computer-controlled adaptive KAFO (Ottobock C-Brace). All subjects performed a structured set of functional activities while wearing an accelerometer on their waist, and random forest classifiers were used as activity classification models. We examined both global models, which are trained on other subjects (healthy or disabled individuals), and personal models, which are trained and tested on the same subject. Results Median accuracies of global and personal models trained with data from the new KAFO were significantly higher (61% and 76%, respectively) than those of models that use data from the original KAFO (55% and 66%, respectively) (Wilcoxon signed-rank test, P=.006 and P=.01). These models also massively outperformed a global model trained on healthy subjects, which only achieved a median accuracy of 53%. Device-specific models conferred a major advantage for activity recognition. Conclusions Our results suggest that when patients use a new assistive device, labeled data from activities performed with the specific device are needed for maximal precision activity recognition. Personal device-specific models yield the highest accuracy in such scenarios, whereas models trained on

  17. Activity Recognition in Individuals Walking With Assistive Devices: The Benefits of Device-Specific Models.

    Science.gov (United States)

    Lonini, Luca; Gupta, Aakash; Deems-Dluhy, Susan; Hoppe-Ludwig, Shenan; Kording, Konrad; Jayaraman, Arun

    2017-08-10

    Wearable sensors gather data that machine-learning models can convert into an identification of physical activities, a clinically relevant outcome measure. However, when individuals with disabilities upgrade to a new walking assistive device, their gait patterns can change, which could affect the accuracy of activity recognition. The objective of this study was to assess whether we need to train an activity recognition model with labeled data from activities performed with the new assistive device, rather than data from the original device or from healthy individuals. Data were collected from 11 healthy controls as well as from 11 age-matched individuals with disabilities who used a standard stance control knee-ankle-foot orthosis (KAFO), and then a computer-controlled adaptive KAFO (Ottobock C-Brace). All subjects performed a structured set of functional activities while wearing an accelerometer on their waist, and random forest classifiers were used as activity classification models. We examined both global models, which are trained on other subjects (healthy or disabled individuals), and personal models, which are trained and tested on the same subject. Median accuracies of global and personal models trained with data from the new KAFO were significantly higher (61% and 76%, respectively) than those of models that use data from the original KAFO (55% and 66%, respectively) (Wilcoxon signed-rank test, P=.006 and P=.01). These models also massively outperformed a global model trained on healthy subjects, which only achieved a median accuracy of 53%. Device-specific models conferred a major advantage for activity recognition. Our results suggest that when patients use a new assistive device, labeled data from activities performed with the specific device are needed for maximal precision activity recognition. Personal device-specific models yield the highest accuracy in such scenarios, whereas models trained on healthy individuals perform poorly and should not be

  18. Successful Aging Through Successful Accommodation With Assistive Devices.

    Science.gov (United States)

    Freedman, Vicki A; Kasper, Judith D; Spillman, Brenda C

    2017-03-01

    To provide a profile of older adults who successfully accommodate declines in capacity by using assistive devices. Using the National Health and Aging Trends Study, we provide national estimates of prevalent, incident, and persistent successful accommodation of mobility and self-care activity limitations. For incident and persistent accommodation groups, we describe their subjective wellbeing and participation restrictions, health and functioning, demographic and socioeconomic characteristics, and acquisition of assistive devices and environmental features. We estimate regression models predicting incident and persistent successful accommodation and the extent of wellbeing and participation restrictions for incident and persistent groups (vs. those who are fully able). Nearly one-quarter of older adults have put in place accommodations that allow them to carry out daily activities with no assistance or difficulty. In adjusted models, incident and persistent successful accommodation is more common for those ages 80-89, those with more children, and those living in homes with environmental features already installed; wellbeing levels for these groups are similar and participation restrictions only slightly below those who are fully able. A focus on facilitating successful accommodation among those who experience declines in capacity may be an effective means of promoting participation and wellbeing in later life.

  19. Mobilizing Knowledge: The Evidence Gap for Assistive Devices

    Directory of Open Access Journals (Sweden)

    Edward D. Lemaire

    2016-09-01

    Full Text Available Knowledge mobilization can be hindered in healthcare technology settings where the pace of change outpaces the ability to perform high-quality research methodologies that provide timely knowledge to enable informed prescription and technology application to the end user. Although well-controlled research with appropriate sample sizes is needed, this approach must be balanced with other evidence sources to address the knowledge immediacy requirements. Using carbon-fibre ankle–foot orthoses (i.e., lower-limb braces that improve stability, alignment, and foot-to-ground placement as a case study, various sources of assistive device evidence were explored for their contribution to the continuum of knowledge in this area. A basic level of knowledge exists, but the quality is insufficient to inform the physical rehabilitation community on selecting from the almost 70 different devices on the market and the expected clinical outcomes for a target population. A combination of enhanced single-participant reports should be considered as an important part of the knowledge continuum and essential for knowledge immediacy. This approach must also be expanded to national and multinational database initiatives that provide a better base from which to extract knowledge on assistive device performance and mobilize this knowledge to provide optimal care for people with physical disabilities.

  20. A new "twist" on right heart failure with left ventricular assist systems.

    Science.gov (United States)

    Houston, Brian A; Shah, Keyur B; Mehra, Mandeep R; Tedford, Ryan J

    2017-07-01

    Despite significant efforts to predict and prevent right heart failure, it remains a leading cause of morbidity and mortality after implantation of left ventricular assist systems (LVAS). In this Perspective, we review the underappreciated anatomic and physiologic principles that govern the relationship between left and right heart function and contribute to this phenomenon. This includes the importance of considering the right ventricle (RV) and pulmonary arterial circuit as a coupled system; the contribution of the left ventricle (LV) to RV contractile function and the potential negative impact of acutely unloading the LV; the influence of the pericardium and ventricular twist on septal function; the role of RV deformation in reduced mechanical efficiency after device placement; and the potential of ongoing stressors of an elevated right-sided preload. We believe an appreciation of these complex issues is required to fully understand the expression of the unique phenotypes of right heart failure after LVAS implantation and for developing better prognostic and therapeutic strategies. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  1. [Rehabilitation standards for follow-up treatment and rehabilitation of patients with ventricular assist device (VAD)].

    Science.gov (United States)

    Willemsen, Detlev; Cordes, C; Bjarnason-Wehrens, B; Knoglinger, E; Langheim, E; Marx, R; Reiss, N; Schmidt, T; Workowski, A; Bartsch, P; Baumbach, C; Bongarth, C; Phillips, H; Radke, R; Riedel, M; Schmidt, S; Skobel, E; Toussaint, C; Glatz, J

    2016-03-01

    The increasing use of ventricular assist devices (VADs) in terminal heart failure patients provides new challenges to cardiac rehabilitation physicians. Structured cardiac rehabilitation strategies are still poorly implemented for this special patient group. Clear guidance and more evidence for optimal modalities are needed. Thereby, attention has to be paid to specific aspects, such as psychological and social support and education (e.g., device management, INR self-management, drive-line care, and medication).In Germany, the post-implant treatment and rehabilitation of VAD Patients working group was founded in 2012. This working group has developed clear recommendations for the rehabilitation of VAD patients according to the available literature. All facets of VAD patients' rehabilitation are covered. The present paper is unique in Europe and represents a milestone to overcome the heterogeneity of VAD patient rehabilitation.

  2. Monitoring and Transmission via Wireless Network for an Assistive Device.

    Science.gov (United States)

    Chang, Yi-Chu; Chen, Chiun-Fan; Lin, Hua-Sheng; Chong, Fok-Ching; Luh, Jer-Junn; Lai, Jin-Shin

    2005-01-01

    Owing to the increasing number of disabled individuals, technical aids are acting more aggressively in the era of modern medicine. The M3S (Multiple Master Multiple Slave) system developed for the physically challenged, utilizes intelligent transmission and integration mechanisms to arrange all hooked-up devices with proper control. To overcome certain limitations of the system (e.g. distance), an RF (Radio Frequency) wireless module would be in charge of the wireless communication between a remote bus and a local bus. It is demonstrated here as assistance for parking assistive vehicles (e.g. powered wheelchair) located in a remote region, which also includes monitoring and usage of accessorial data transmissions shown in our man-machine interface.

  3. A Quadratic Nonlinear Prediction-Based Heart Motion Model following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    National Research Council Canada - National Science Library

    Liang, Fan; Meng, Xiaofeng

    2013-01-01

    Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic...

  4. Risk management of developing assistive devices for elderly.

    Science.gov (United States)

    Cheng, Yu-Tien; Chuang, Huan-Ming; Pei, Chun

    2011-01-01

    This study uses the Delphi method in interviewing experts to identify critical risks in the development of assistive devices. Critical risks included product planning, technology development, production, performance, schedule management, and cost management, comprising 26 risk factors in 6 constructs. This study determined which factors were of high importance, finding a total of 7 market analysis errors. Mind mapping was used to create a knowledge map; and layer expansion was used to understand risk distribution to facilitate risk mitigation and monitoring. Organizational risk strategies could be developed to reduce risk and maintain stability while achieving the objective of developing new products. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  5. 47 CFR 74.870 - Wireless video assist devices.

    Science.gov (United States)

    2010-10-01

    ...°03′15.0″ 118°14′31.3″ 470-476 14 476-482 15 482-488 16 488-494 17 500-506 19 506-512 20 512-518 21... picture and television producers, as defined in § 74.801 may operate wireless video assist devices on a...″ 75°09′19.6″ 494-500 18 500-506 19 506-512 20 512-518 21 Pittsburgh, PA 40°26′19.2″ 79°59′59.2″ 470...

  6. Interjoint coordination and the personal lift-assist device.

    Science.gov (United States)

    Graham, Ryan B; Smallman, Catherine L W; Sadler, Erin M; Stevenson, Joan M

    2013-04-01

    It has been suggested that interjoint coordination may serve to reduce joint stress and muscular demand and to maintain balance during dynamic lifting tasks, thus having implications for safe lifting practices. Before recommending the use of an on-body ergonomic aid, the Personal Lift-Assist Device (PLAD), it is important to determine any effects this device may have on interjoint coordination. Principal component analyses were applied to relative phase angle waveforms, defining the hip-knee and lumbar spine-hip coordination of 15 males and 15 females during a repetitive lifting task. When wearing the PLAD, users lifted with more synchronous hip-knee and lumbar spine-hip coordination patterns (P lift (P < .01) for all conditions. No significant main effects of sex or significant interactions were observed on any of the outcome variables.

  7. Perioperative management of two patients with left ventricular assist devices presenting for noncardiac surgery in the prone position.

    Science.gov (United States)

    Chacon, M Megan; Hattrup, Emily A; Shillcutt, Sasha K

    2014-03-15

    Ventricular assist devices (VADs) provide mechanical circulatory support for patients with advanced heart failure. Patients with VADs are presenting for noncardiac surgery with increasing frequency. Understanding anesthetic management of patients with VADs is timely and necessary for perioperative physicians. We present 2 patients supported by left VADs who required intraoperative prone positioning, and how transesophageal echocardiography and VAD variables can be used to guide management.

  8. Activity Recognition in Individuals Walking With Assistive Devices: The Benefits of Device-Specific Models

    OpenAIRE

    Lonini, Luca; Gupta, Aakash; Deems-Dluhy, Susan; Hoppe-Ludwig, Shenan; Kording, Konrad; Jayaraman, Arun

    2017-01-01

    Background Wearable sensors gather data that machine-learning models can convert into an identification of physical activities, a clinically relevant outcome measure. However, when individuals with disabilities upgrade to a new walking assistive device, their gait patterns can change, which could affect the accuracy of activity recognition. Objective The objective of this study was to assess whether we need to train an activity recognition model with labeled data from activities performed wit...

  9. Application of the moving-actuator type pump as a ventricular assist device: in vitro and in vivo studies.

    Science.gov (United States)

    Lee, H S; Rho, Y R; Park, C Y; Hwang, C M; Kim, W G; Sun, K; Choi, M J; Lee, K K; Cheong, J T; Shim, E B; Min, B G

    2002-06-01

    A moving actuator type pump has been developed as a multifunctional Korean artificial heart (AnyHeart). The pump consists of a moving actuator as an energy converter, right and left sacs, polymer (or mechanical) valves, and a rigid polyurethane housing. The actuator containing a brushless DC motor moves back and forth on an epicyclical gear train to produce a pendular motion, which compresses both sacs alternately. Of its versatile functions of ventricular assist device and total artificial heart use, we have evaluated the system performance as a single or biventricular assist device through in vitro and in vivo experiments. Pump performance and anatomical feasibility were tested using various animals of different sizes. In the case of single ventricular assist device (VAD) use, one of the sacs remained empty and a mini-compliance chamber was attached to either an outflow or inflow port of the unused sac. The in vitro and in vivo studies show acceptable performance and pump behavior. Further extensive study is required to proceed to human application.

  10. Left Ventricular Assist Device Malfunctions: It Is More Than Just the Pump.

    Science.gov (United States)

    Kormos, Robert L; McCall, Michael; Althouse, Andrew; Lagazzi, Luigi; Schaub, Richard; Kormos, Michael A; Zaldonis, Jared A; Sciortino, Christopher; Lockard, Kathleen; Kuntz, Nicole; Dunn, Elizabeth; Teuteberg, Jeffrey J

    2017-10-31

    Reports of left ventricular assist device (LVAD) malfunction have focused on pump thrombosis. However, the device consists of the pump, driveline, and peripherals, all of which are potentially subject to failure. Prospectively collected data were reviewed for all LVAD device malfunctions (DMs) occurring in rotary LVADs implanted at a single center between April 2004 and May 2016. Durable LVADs included 108 Heartmate II (HM II) and 105 HeartWare VAD (HVAD). DM data were categorized according to device type and into categories related to the component that failed: (1) controller, (2) peripheral components, and (3) implantable blood pump or its integral electric driveline. Pump-related events were analyzed as pump-specific (suspected or confirmed thrombosis) or nonpump-specific (driveline failure). DM rates were reported as events per 1000 patient-days, and Cox proportional hazard models were used for time-to-event analyses. Cumulative rates of malfunction were examined for the main components of each type of LVAD. Types of DM included controller failure (30%), battery failure (19%), or patient cable failure (14%), whereas only 13% were because of pump failure. DMs were more common in the HM II device (3.73 per 1000 patient-days versus 3.06 per 1000 patient-days for the HVAD, P pump-specific malfunctions was discovered in those implanted with an HM II versus an HVAD (0.55 versus 0.39, respectively; P pump-specific malfunction at 3 years compared with 56% for the HM II (log-rank P pump thrombosis at 3 years compared with 90% of the patients with HVAD. Freedom from failure of the integrated driveline was 79% at 3 years for the HM II but 100% for the HVAD (log-rank P pump failure alone and occurs for different components at different rates based on the type of LVAD. © 2017 American Heart Association, Inc.

  11. An Implantable Intravascular Pressure Sensor for a Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Luigi Brancato

    2016-08-01

    Full Text Available The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD. A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick film process. A commercial sub-millimeter piezoresistive sensor is attached to an alumina substrate, and a double coating of polydimethylsiloxane (PDMS and parylene-C is applied. The final size of the packaged device is 2.6 mm by 3.6 mm by 1.8 mm. A prototype electronic circuit for conditioning and read-out of the pressure signal is developed, satisfying the VAD-specific requirements of low power consumption (less than 14.5 mW in continuous mode and small form factor. The packaged sensor has been submitted to extensive in vitro tests. The device displayed a temperature-independent sensitivity (12 μ V/V/mmHg and good in vitro stability when exposed to the continuous flow of saline solution (less than 0.05 mmHg/day drift after 50 h. During in vivo validation, the transducer has been successfully used to record the arterial pressure waveform of a female sheep. A small, intravascular sensor to continuously register the blood pressure at the inflow and the outflow of a VAD is developed and successfully validated in vivo.

  12. A Quadratic Nonlinear Prediction-Based Heart Motion Model following Control Algorithm in Robotic-Assisted Beating Heart Surgery

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-01-01

    Full Text Available Off-pump coronary artery bypass graft surgery outperforms the traditional on-pump surgery because the assisted robotic tools can cancel the relative motion between the beating heart and the robotic tools, which reduces post-surgery complications for patients. The challenge for the robot assisted tool when tracking the beating heart is the abrupt change caused by the nonlinear nature of heart motion and high precision surgery requirements. A characteristic analysis of 3D heart motion data through bi-spectral analysis demonstrates the quadratic nonlinearity in heart motion. Therefore, it is necessary to introduce nonlinear heart motion prediction into the motion tracking control procedures. In this paper, the heart motion tracking problem is transformed into a heart motion model following problem by including the adaptive heart motion model into the controller. Moreover, the model following algorithm with the nonlinear heart motion model embedded inside provides more accurate future reference by the quadratic term of sinusoid series, which could enhance the tracking accuracy of sharp change point and approximate the motion with sufficient detail. The experiment results indicate that the proposed algorithm outperforms the linear prediction-based model following controller in terms of tracking accuracy (root mean square.

  13. Incidence and predictors of cognitive decline in patients with left ventricular assist devices.

    Science.gov (United States)

    Fendler, Timothy J; Spertus, John A; Gosch, Kensey L; Jones, Philip G; Bruce, Jared M; Nassif, Michael E; Flint, Kelsey M; Dunlay, Shannon M; Allen, Larry A; Arnold, Suzanne V

    2015-05-01

    After left ventricular assist device (LVAD) placement for advanced heart failure, increased cerebral perfusion should result in improved cognitive function. However, stroke (a well-known LVAD complication) and subclinical cerebral ischemia may result in transient or permanent cognitive decline. We sought to describe the incidence and predictors of cognitive decline after LVAD using a valid, sensitive assessment tool. Among 4419 patients in the Interagency Registry for Mechanically Assisted Circulatory Support who underwent LVAD implantation between May 2012 and December 2013, cognitive function was assessed in 1173 patients with the Trail Making B Test before LVAD and at 3, 6, and 12 months. The test detects several forms of cognitive impairment, including subclinical stroke. Cognitive decline was defined as a clinically important increase during follow-up using a moderate Cohen d effect size of 0.5×baseline SD (32 s). The cumulative incidence of cognitive decline in the year after LVAD implantation, treating death and transplantation as competing risks, was 29.2%. In adjusted analysis, older age (≥70 versus decline. Cognitive decline occurs commonly in patients in the year after LVAD and is associated with older age and destination therapy. These results could have important implications for patient selection and improved communication of risks before LVAD implantation. Additional studies are needed to explore the association between cognitive decline and subsequent stroke, health status, and mortality in patients after LVAD. © 2015 American Heart Association, Inc.

  14. Self-assessment of classroom assistive listening devices.

    Science.gov (United States)

    Odelius, Johan; Johansson, Orjan

    2010-07-01

    Self-assessment of classroom assistive listening devices (ALDs) based on induction loop systems was carried out in Swedish classes for hearing-impaired students. A questionnaire was developed and completed by 25 students (bilateral hearing aid users, 10-20 years old). Responses for hearing aid microphone mode (M) and telecoil mode (T) were collected. Two attributes, audibility and awareness, were identified and assigned to either mode. Better audibility was achieved in T-mode. Students with severe hearing loss benefited more using T-mode when compared to the better hearing students, especially in more difficult listening situations. Better awareness was achieved in M-mode; students could better hear, locate and segregate sounds in the environment around them. Depending on the situation, students make different choices between audibility and awareness. Self-assessment is a promising approach for determining what combination of ALD design and function that will best benefit the students.

  15. Left ventricular assist device hemolysis leading to dysphagia.

    Science.gov (United States)

    Wuschek, Alexander; Iqbal, Sara; Estep, Jerry; Quigley, Eamonn; Richards, David

    2015-05-14

    A 41-year-old man with a continuous-flow left ventricular assist device presented for evaluation of dysphagia and dark urine. He was found to have a significantly elevated L-lactate dehydrogenase and an elevated plasma free hemoglobin consistent with intravascular hemolysis. After the hemolysis ceased, both the black urine and dysphagia resolved spontaneously. Transient esophageal dysfunction, as a manifestation of gastrointestinal dysmotility, is known to occur in the setting of hemolysis. Paroxysmal nocturnal hemoglobinuria is another recognized cause of massive hemolysis with gastrointestinal dysmotility occurring in 25%-35% of patients during a paroxysm. Intravascular hemolysis increases plasma free hemoglobin, which scavenges nitric oxide (NO), an important second messenger for smooth muscle cell relaxation. The decrease in NO can lead to esophageal spasm and resultant dysphagia. In our patient the resolution of hemolysis resulted in resolution of dysphagia.

  16. Accurate diagnoses, evidence based drugs, and new devices (3 Ds in heart failure

    Directory of Open Access Journals (Sweden)

    Bambang B. Siswanto

    2012-02-01

    Full Text Available Heart failure becomes main problem in cardiology because of increasing of heart failure patients, rehospitalization rate, morbidity, and mortality rate. The main causes of increasing heart failure problems are: (1 Successful treatment of acute myocardial infarction can be life saving, but its sequelae can cause heart failure. (2 Increasing life expectancy rate grows along with incidences of ageing related heart failure. (3 High prevalence of infection in Indonesia can cause rheumatic heart disease post Streptococcal beta hemolyticus infection, viral myocarditis, infective endocartitis, and tuberculoid pericarditis. (4 Many risk factors for coronary heart disease are often found in heart failure patients, for examples smoking, diabetes, hypercholesterolemia, hypertension, and obesity. Indonesia joined international multicentered registry in 2006. Acute Decompensated HEart failure REgistry is a web based international registry to record patient with acute decompensated heart failure treated in emergency room. It was found that heart failure patients in 5 big hospitals in Java and Bali island that joined this registry are younger, sicker and late to seek treatment. The median hospital length of stay was 7 days and in hospital mortality rate was 6.7%. The aim of this article is to give summary about essential things in diagnosing and treating heart failure patients. 3D (accurate diagnoses, evidence based drugs, and new devices are the most important but what to do and what not to do in dealing with heart failure is also useful for your daily practice. (Med J Indones 2012;21:52-8Keywords: Devices, diagnostic, drugs, heart failure

  17. Ventricular assist devices as destination therapy: psychosocial and ethical implications.

    Science.gov (United States)

    Grogan, Sherry; Kostick, Kristin; Delgado, Estevan; Bruce, Courtenay R

    2015-01-01

    One of the candidate evaluation challenges is determining when and how psychosocial domains influence short- and long-term destination therapy ventricular assist device (DT-VAD) outcomes. There are very few DT-VAD studies and no validated instruments to identify psychosocial risk factors. General practice is to borrow from the transplant literature, which may not be applicable to this unique device application. We question the relevance of using transplant psychosocial evaluation for patients who are candidates for DT-VAD only, particularly because these patients require a certain level of cognitive, psychological, and behavioral functioning to ensure proper long-term self-care with the VAD. We may be missing important psychological characteristics in our pre-evaluations by "borrowing" from the transplant literature, thereby underplaying significant factors that are especially relevant for DT-VAD candidates. Conversely, we may be screening out candidates who may benefit greatly from DT-VAD by using transplant criteria as part of the screening process. We use a case study to illustrate some of the challenges of weighing psychosocial risk factors in the DT-VAD population and to emphasize the need for developing distinct psychosocial assessment criteria for DT-VAD patients.

  18. Simulation based efficiency prediction of a Brushless DC drive applied in ventricular assist devices.

    Science.gov (United States)

    Pohlmann, André; Hameyer, Kay

    2012-01-01

    Ventricular Assist Devices (VADs) are mechanical blood pumps that support the human heart in order to maintain a sufficient perfusion of the human body and its organs. During VAD operation blood damage caused by hemolysis, thrombogenecity and denaturation has to be avoided. One key parameter causing the blood's denaturation is its temperature which must not exceed 42 °C. As a temperature rise can be directly linked to the losses occuring in the drive system, this paper introduces an efficiency prediction chain for Brushless DC (BLDC) drives which are applied in various VAD systems. The presented chain is applied to various core materials and operation ranges, providing a general overview on the loss dependencies.

  19. In-vitro Evaluation of Ventricular Cannulation for Rotodynamic Cardiac Assist Devices

    Science.gov (United States)

    Bachman, Timothy N; Bhama, Jay K; Verkaik, Josiah; Vandenberghe, Stijn; Kormos, Robert L; Antaki, James F

    2012-01-01

    The influence of positioning and geometry of ventricular cannulas for contemporary continuous flow Left Ventricular Assist Devices (LVADs) was evaluated in a non-beating isolated heart preparation with borescopic visualization. Preload and LVAD flow were varied to evaluate degrees of ventricular decompression up to the point of ventricular collapse. The performance of a flanged cannula was compared to a conventional bevel-tipped cannula: quantitatively by the maximal flow attainable, and qualitatively by visualization of fluid tracer particles within the ventricular chamber. Three forms of ventricular suck-down occurred: concentric collapse, gradual entrainment and instantaneous entrainment. In some circumstances, unstable oscillations of the ventricle were observed prior to complete collapse. Under conditions of low preload, the flanged cannula demonstrated less positional sensitivity, provided greater flow, and exhibited fewer areas of stagnation than the beveled cannula. These observations warrant further consideration of a flanged ventricular cannula to mitigate complications encountered with conventional cannulae. PMID:22563363

  20. In Vitro Durability - Pivot bearing with Diamond Like Carbon for Ventricular Assist Devices

    CERN Document Server

    de Sá, Rosa Corrêa Leoncio; Leão, Tarcísio Fernandes; da Silva, Evandro Drigo; da Fonseca, Jeison Willian Gomes; da Silva, Bruno Utiyama; Leal, Edir Branzoni; Moro, João Roberto; de Andrade, Aron José Pazin; Bock, Eduardo Guy Perpétuo

    2015-01-01

    Institute Dante Pazzanese of Cardiology (IDPC) develops Ventricular Assist Devices (VAD) that can stabilize the hemodynamics of patients with severe heart failure before, during and/or after the medical practice; can be temporary or permanent. The ADV's centrifugal basically consist of a rotor suspended for system pivoting bearing; the PIVOT is the axis with movement of rotational and the bearing is the bearing surface. As a whole system of an implantable VAD should be made of long-life biomaterial so that there is no degradation or deformation during application time; surface modification techniques have been widely studied and implemented to improve properties such as biocompatibility and durability of applicable materials. The Chemical Vapour Deposition technique allows substrates having melting point higher than 300 {\\deg}C to be coated, encapsulated, with a diamond like carbon film (DLC); The test simulated the actual conditions in which the system of support remains while applying a ADV. The results hav...

  1. Cardiogenic shock associated with loco-regional anesthesia rescued with left ventricular assist device implantation

    Directory of Open Access Journals (Sweden)

    Droogan Christopher

    2010-12-01

    Full Text Available Abstract A healthy 53 year old man developed profound cardiogenic shock following instillation of bupivacaine-lidocaine-epinephrine solution as a locoregional anesthetic for elective outpatient shoulder surgery. Intubation, resuscitation, and transfer to the nearby hospital were done: echocardiography showed profound biventricular dysfunction; cardiac catheterization showed normal coronary arteries. Despite placement of an intra-aortic balloon pump and intravenous vasoactive drugs, the patient remained in shock. Stabilization was achieved with emergent institution of cardiopulmonary bypass and placement of a temporary left ventricular assist device (LVAD. Twenty-four hours later, cardiac function normalized and the LVAD was removed. The patient was discharged five days later and remained with normal heart function in three-year follow-up.

  2. Medical Devices; Immunology and Microbiology Devices; Classification of the Automated Indirect Immunofluorescence Microscope and Software-Assisted System. Final order.

    Science.gov (United States)

    2017-11-14

    The Food and Drug Administration (FDA or we) is classifying the automated indirect immunofluorescence microscope and software-assisted system into class II (special controls). The special controls that apply to the device type are identified in this order and will be part of the codified language for the automated indirect immunofluorescence microscope and software-assisted system's classification. We are taking this action because we have determined that classifying the device into class II (special controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

  3. Recovery of Serum Cholesterol Predicts Survival After Left Ventricular Assist Device Implantation

    Science.gov (United States)

    Vest, Amanda R.; Kennel, Peter J.; Maldonado, Dawn; Young, James B.; Mountis, Maria M.; Naka, Yoshifumi; Colombo, Paolo C.; Mancini, Donna M.; Starling, Randall C.; Schulze, P. Christian

    2017-01-01

    Background Advanced systolic heart failure is associated with myocardial and systemic metabolic abnormalities, including low levels of total cholesterol and low-density lipoprotein. Low cholesterol and low-density lipoprotein have been associated with greater mortality in heart failure. Implantation of a left ventricular assist device (LVAD) reverses some of the metabolic derangements of advanced heart failure. Methods and Results A cohort was retrospectively assembled from 2 high-volume implantation centers, totaling 295 continuous-flow LVAD recipients with ≥2 cholesterol values available. The cohort was predominantly bridge-to-transplantation (67%), with median age of 59 years and 49% ischemic heart failure cause. Total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride levels all significantly increased after LVAD implantation (median values from implantation to 3 months post implantation 125–150 mg/dL, 67–85 mg/dL, 32–42 mg/dL, and 97–126 mg/dL, respectively). On Cox proportional hazards modeling, patients achieving recovery of total cholesterol levels, defined as a median or greater change from pre implantation to 3 months post-LVAD implantation, had significantly better unadjusted survival (hazard ratio, 0.445; 95% confidence interval, 0.212–0.932) and adjusted survival (hazard ratio, 0.241; 95% confidence interval, 0.092–0.628) than those without cholesterol recovery after LVAD implantation. The continuous variable of total cholesterol at 3 months post implantation and the cholesterol increase from pre implantation to 3 months were also both significantly associated with survival during LVAD support. Conclusions Initiation of continuous-flow LVAD support was associated with significant recovery of all 4 lipid variables. Patients with a greater increase in total cholesterol by 3 months post implantation had superior survival during LVAD support. PMID:27623768

  4. Towards active tracking of beating heart motion in the presence of arrhythmia for robotic assisted beating heart surgery.

    Science.gov (United States)

    Tuna, E Erdem; Karimov, Jamshid H; Liu, Taoming; Bebek, Özkan; Fukamachi, Kiyotaka; Çavuşoğlu, M Cenk

    2014-01-01

    In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion.

  5. Towards active tracking of beating heart motion in the presence of arrhythmia for robotic assisted beating heart surgery.

    Directory of Open Access Journals (Sweden)

    E Erdem Tuna

    Full Text Available In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion.

  6. Ergonomic evaluation of a wearable assistive device for overhead work.

    Science.gov (United States)

    Rashedi, Ehsan; Kim, Sunwook; Nussbaum, Maury A; Agnew, Michael J

    2014-01-01

    Overhead work is an important risk factor for upper extremity (UE) musculoskeletal disorders. We examined the potential of a mechanical arm and an exoskeletal vest as a wearable assistive device (WADE) for overhead work. Twelve participants completed 10 minutes of simulated, intermittent overhead work, using each of three payloads (1.1, 3.4 and 8.1 kg) and with/without the WADE. Ratings of perceived discomfort (RPDs) and electromyography (EMG) were obtained for the upper arms, shoulders and low back. Using the WADE, UE RPDs decreased by ∼50% with the heavier payloads, whereas smaller (∼25%) and non-significant increases in low-back RPDs were found and were relatively independent of payload. Changes in RPDs with WADE use were consistent with physical demands indicated by EMG, though EMG-based differences in fatigue were less apparent. Participants generally preferred using the WADE, particularly with heavier payloads. These results supported the potential utility of a WADE as an intervention for overhead work.

  7. Multicenter Evaluation of Octreotide as Secondary Prophylaxis in Patients With Left Ventricular Assist Devices and Gastrointestinal Bleeding.

    Science.gov (United States)

    Shah, Keyur B; Gunda, Sampath; Emani, Sitaramesh; Kanwar, Manreet K; Uriel, Nir; Colombo, Paolo C; Uber, Patricia A; Sears, Melissa L; Chuang, Joyce; Farrar, David J; Brophy, Donald F; Smallfield, George B

    2017-11-01

    Gastrointestinal (GI) bleeding is one of the most common complications after continuous-flow left ventricular assist device implantation. More than one third of patients with incident bleed go on to develop recurrent GI bleeding. Octreotide, a somatostatin analog, is proposed to reduce the risk of recurrent GI bleeding in this population. This multicenter, retrospective analysis evaluated 51 continuous-flow left ventricular assist device patients who received secondary prophylaxis with octreotide after their index GI bleed from 2009 to 2015. All patients had a hospitalization for GI bleed and received octreotide after discharge. Patient demographics, medical and medication history, and clinical characteristics of patients who rebled after receiving octreotide were compared with non-rebleeders. These data were also compared with matched historical control patients previously enrolled in the HMII (HeartMate II) clinical trials, none of whom received octreotide, to provide a context for the bleeding rates. Twelve patients (24%) who received secondary octreotide prophylaxis developed another GI bleed, whereas 39 (76%) did not. There were similar intergroup demographics; however, significantly more bleeders had a previous GI bleeding history before left ventricular assist device placement (33% versus 5%; P=0.02) and greater frequency of angiodysplasia confirmed during endoscopy (58% versus 23%; P=0.03). Fewer patients in this study experienced a recurrent GI bleed compared with a matched historical control group that did not receive octreotide (24% versus 43%; P=0.04). Patients with continuous-flow left ventricular assist device receiving secondary prophylaxis with octreotide had a significantly lower GI bleed recurrence compared with historical controls not treated with octreotide. Additional prospective studies are needed to confirm these data. © 2017 American Heart Association, Inc.

  8. Resolution of heart block after surgical removal of an amplatzer device.

    Science.gov (United States)

    Clark, Joseph B; Chowdhury, Devyani; Pauliks, Linda B; Weber, Howard S

    2010-05-01

    A large secundum atrial septal defect in a 4-year-old child was closed by percutaneous placement of an Amplatzer septal occluder (AGA Medical Corporation, Plymouth, MN). After device placement, complete heart block developed that did not resolve after 3 days of medical management. The patient subsequently underwent surgical removal of the device and suture closure of the atrial septal defect. The patient recovered conduction after the operation. We report the successful treatment of device-induced heart block with surgical removal of the device. Copyright (c) 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  9. In-vivo evaluation of the HIA-VAD: : a new German ventricular assist device

    NARCIS (Netherlands)

    Rakhorst, G.; Hensens, A. G.; Verkerke, G. J.; Blanksma, P. K.; Bom, V. J. J.; Elstrodt, J.; Magielse, C. P. E.; van der Meer, J; Ruel, H.

    Helmholtz Ventricular Assist Devices (VAD) are pneumatically driven polyurethane membrane pumps with various volumes. The pumps are placed paracorporeally and connected with commercially available cannulas between the left atrium and aorta (left ventricular assist device) and/or right atrium and

  10. 38 CFR 17.152 - Devices to assist in overcoming the handicap of deafness.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Devices to assist in overcoming the handicap of deafness. 17.152 Section 17.152 Pensions, Bonuses, and Veterans' Relief DEPARTMENT... in overcoming the handicap of deafness. Devices for assisting in overcoming the handicap of deafness...

  11. An unknown complication of peripherally inserted central venous catheter in a patient with ventricular assist device

    Directory of Open Access Journals (Sweden)

    Parikh M

    2011-01-01

    Full Text Available We report an unknown complication of peripherally inserted central venous catheter in a patient with Ventricular Assist Device. This rare complication led to the failure of the right ventricular assist device, which could be detrimental in patients with dilated cardiomyopathy.

  12. A novel implantable electromechanical ventricular assist device - First acute animal testing

    NARCIS (Netherlands)

    Kaufmann, R; Rakhorst, G; Mihaylov, D; Elstrodt, J; Nix, C; Reul, H; Rau, G

    1997-01-01

    A novel ventricular assist device (HIA-EMLVAD-AT1, Helmholtz Institute Aachen-electromechanical Left Ventricular Assist Device-Animal Test Version 1), driven by a uniformly and unidirectionally rotating actuator and a patented hypocycloidic pusherplate displacement gear unit, was developed and

  13. Fundus fluorescein angiographic findings in patients who underwent ventricular assist device implantation.

    Science.gov (United States)

    Ozturk, Taylan; Nalcaci, Serhad; Ozturk, Pelin; Engin, Cagatay; Yagdi, Tahir; Akkin, Cezmi; Ozbaran, Mustafa

    2013-09-01

    Disruption of microcirculation in various tissues as a result of deformed blood rheology due to ventricular assist device (VAD) implantation causes novel arteriovenous malformations. Capillary disturbances and related vascular leakage in the retina and choroidea may also be seen in patients supported by VADs. We aimed to evaluate retinal vasculature deteriorations after VAD implantation. The charts of 17 patients who underwent VAD implantation surgery for the treatment of end-stage heart failure were retrospectively reviewed. Eight cases (47.1%) underwent pulsatile pump implantation (Berlin Heart EXCOR, Berlin Heart Mediprodukt GmbH, Berlin, Germany); however, nine cases (52.9%) had continuous-flow pump using centrifugal design (HeartWare, HeartWare Inc., Miramar, FL, USA). Study participants were selected among the patients who had survived with a VAD for at least 6 months, and results of detailed ophthalmologic examinations including optic coherence tomography (OCT) and fundus fluorescein angiography (FA) were documented. All of the 17 patients were male, with a mean age of 48.5 ± 14.8 years (15-67 years). Detailed ophthalmologic examinations including the evaluation of retinal vascular deteriorations via FA were performed at a mean of 11.8 ± 3.7 months of follow-up (6-18 months). Mean best-corrected visual acuity and intraocular pressure were found as logMAR 0.02 ± 0.08 and 14.6 ± 1.9 mm Hg, respectively in the study population. Dilated fundoscopy revealed severe focal arteriolar narrowing in two patients (11.8%), and arteriovenous crossing changes in four patients (23.5%); however, no pathological alteration was present in macular OCT scans. In patients with continuous-flow blood pumps, mean arm-retina circulation time (ARCT) and arteriovenous transit time (AVTT) were found to be 16.8 ± 3.0 and 12.4 ± 6.2 s, respectively; whereas those with pulsatile-flow blood pumps were found to be 17.4 ± 3.6 and 14.0 ± 2.1 s in patients (P=0.526 and P=0

  14. Content Analysis of Social Media Related to Left Ventricular Assist Devices.

    Science.gov (United States)

    Kostick, Kristin M; Blumenthal-Barby, Jennifer S; Wilhelms, Lidija A; Delgado, Estevan D; Bruce, Courtenay R

    2015-09-01

    Social media have the potential to offer important benefits for patient education, support, and shared decision making. Despite the proliferation of social media use during the past decade, little is known about the scope and quality of available information, or the purposes that social media sites serve for patient decisional and support needs. We conducted a mixed method study, including content analysis of social media and principal components analysis analysis of data sites discussing left ventricular assist device treatment for heart failure. This study explored aspects of interactivity, user-friendliness, appeal, medium, purpose, audience, and accuracy of information. Higher levels of interactivity (eg, posting comments) seem to enhance the appeal and usability of available information but also introduce greater potential for inaccuracy and inconsistency. The current lack of oversight into the content and quality of available information constitute a challenge for the reliable use of social media as forums for information-seeking and social network-based support. We conclude that social media outlets constitute a promising source of informational and psychosocial support for patients, caregivers, and candidates, and if used in conjunction with patient-provider dialog, can contribute to informed decision making by facilitating reflection and discussion of personal concerns, values, and informational needs. © 2015 American Heart Association, Inc.

  15. Anesthesia for left ventricular assist device insertion: a case series and review.

    Science.gov (United States)

    Broussard, David; Donaldson, Emilie; Falterman, Jason; Bates, Michael

    2011-01-01

    From October 2008 to June 2010, a total of 42 patients had the HeartMate II left ventricular assist device inserted surgically at Ochsner Medical Center in New Orleans, LA. A retrospective electronic record review was conducted on this series of patients to analyze elements of perioperative anesthetic care, including general anesthetic care, echocardiographic considerations, and blood product usage. Etomidate was used to induce anesthesia for 34 of 42 patients (81%) in this series, with an average dose of 16.5 mg (±6 mg). The average intraoperative fentanyl dose was 1,318 µg (±631 µg). On average, patients were extubated 91 hours (±72 hours) after arrival to the intensive care unit and left on day 9 (±5 days). The average left ventricular ejection fraction of the patients in this series was 13% (±5%). Sixteen patients were evaluated as having severe right-heart dysfunction preoperatively. Two of 42 patients required surgical closure of echocardiographically identified patent foramen ovale. Twelve of 42 patients underwent surgical correction of tricuspid regurgitation. On average, 3 units (±2.6 units) of fresh frozen plasma were transfused intraoperatively and 10 units postoperatively. Intraoperative red blood cell usage averaged 1.1 units (maximum, 7 units), with an average 9.3 units administered in the first 48 hours postoperatively.

  16. Characteristics of the electrocardiogram in patients with continuous-flow left ventricular assist devices.

    Science.gov (United States)

    Martinez, Sara C; Fansler, Derrick; Lau, Jeffrey; Novak, Eric L; Joseph, Susan M; Kleiger, Robert E

    2015-01-01

    Electrocardiograms (ECGs) are routinely obtained in patients with advanced congestive heart failure (CHF) before and after surgical implantation with a left-ventricular assist device (LVAD). As the number of patients with CHF is increasing, it is necessary to characterize the changes present in the ECG of patients with LVADs. ECGs of 43 patients pre- and postimplantation of a HeartMate II LVAD were compared to characterize the presence of an LVAD using the following six criteria (LVADS2 ): low limb-lead voltage, ventricular pacing, artifact (electrical), duration of the QRS > 120 milliseconds, ST-elevation in the lateral leads, and splintering of the QRS complex. Additionally, 50 ECGs of non-LVAD patients coded as "lateral myocardial infarction (MI)" and 50 ECGs coded as "ventricular pacing" were chosen at random and scored. Odds ratios were calculated using Fisher's exact test. Logistic regression models were built to predict the presence of an LVAD in all patients. Univariate analysis of the pre- and post-LVAD ECGs confirmed that all criteria except the "Duration of QRS > 120 milliseconds" characterized the ECG of a patient with an LVAD. Electrical artifact and low limb-lead voltage yielded the greatest association with an LVAD-ECG. The ECG of a patient with end-stage CHF significantly changes with LVAD implantation. The LVADS2 criteria provide a framework towards characterizing and establishing a new baseline of the ECG in a patient with a continuous-flow LVAD. © 2014 Wiley Periodicals, Inc.

  17. Risk Factors of Gastrointestinal Bleeding After Continuous Flow Left Ventricular Assist Device.

    Science.gov (United States)

    Balcioglu, Ozlem; Kemal, Hatice S; Ertugay, Serkan; Ozturk, Pelin; Engin, Yaprak; Nalbantgil, Sanem; Engin, Cagatay; Yagdi, Tahir; Ozbaran, Mustafa

    2017-09-27

    This study aimed to compare von Willebrand factor (vWF) levels, ristocetin cofactor levels, platelet counts, aortic valve movements, and right heart failure (RHF) as risk factors of gastrointestinal (GI) bleeding in patients with continuous flow left ventricular assist device (cf-LVAD). In a single centre, 90 patients (mean age 52.0 ± 10.5 years), of which 59 were male and 31 were female, had cf-LVAD implantation from October 2010 to November 2012. Seventy-six (84.4%) patients had HeartWare (Medtronic, Mounds View, MN) and 14 (15.5%) had Heartmate II (Thoratec, Pleasanton, CA) implanted. vWF level, ristocetin cofactor level, and platelet count were measured before and after implantation to determine the presence of acquired von Willebrand Syndrome; aortic valve movement and postoperative RHF were evaluated to compare the difference in bleeding and nonbleeding patient groups. Fifteen patients (16.6%) suffered GI bleeding after cf-LVAD implantation. A statistically significant decrease was found in vWF and ristocetin cofactor levels from preoperative period to postoperative period in both bleeding and nonbleeding patient groups (p RHF incidence was significantly high in the bleeding patient group compared with the nonbleeding group (p RHF was an important risk factor for GI bleeding.

  18. Effects of Sevoflurane and Propofol on Organ Blood Flow in Left Ventricular Assist Devices in Pigs

    Directory of Open Access Journals (Sweden)

    Paloma Morillas-Sendín

    2015-01-01

    Full Text Available The aim of this study was to assess the effect of sevoflurane and propofol on organ blood flow in a porcine model with a left ventricular assist device (LVAD. Ten healthy minipigs were divided into 2 groups (5 per group according to the anesthetic received (sevoflurane or propofol. A Biomedicus centrifugal pump was implanted. Organ blood flow (measured using colored microspheres, markers of tissue injury, and hemodynamic parameters were assessed at baseline (pump off and after 30 minutes of partial support. Blood flow was significantly higher in the brain (both frontal lobes, heart (both ventricles, and liver after 30 minutes in the sevoflurane group, although no significant differences were recorded for the lung, kidney, or ileum. Serum levels of alanine aminotransferase and total bilirubin were significantly higher after 30 minutes in the propofol group, although no significant differences were detected between the groups for other parameters of liver function, kidney function, or lactic acid levels. The hemodynamic parameters were similar in both groups. We demonstrated that, compared with propofol, sevoflurane increases blood flow in the brain, liver, and heart after implantation of an LVAD under conditions of partial support.

  19. Postimplant left ventricular assist device fit analysis using three-dimensional reconstruction.

    Science.gov (United States)

    Truong, Thang V; Stanfield, J Ryan; Chaffin, John S; Elkins, C Craig; Kanaly, Paul J; Horstmanshof, Douglas A; Long, James W; Snyder, Trevor A

    2013-01-01

    Left ventricular assist devices (LVADs) are blood pumps that augment the function of the failing heart to improve perfusion, resulting in improved survival. For LVADs to effectively unload the left ventricle, the inflow cannula (IC) should be unobstructed and ideally aligned with the heart's mitral valve (MV). We examined IC orientation deviation from a hypothesized conventional angle (45° right-posterior) and the approximate angle for direct IC-MV alignment in many patients. Three-dimensional anatomic models were created from computed tomography scans for 24 LVAD-implanted patients, and angles were measured between the IC and the apical z-axis in both the coronal and the sagittal planes. Common surgical IC angulation was found to be 22 ± 15° rightward and 21 ± 12° posterior from the apical z-axis; 38% (n = 9) of patients fell in this range. Direct IC-MV angulation was found to be 34 ± 8° rightward and 15 ± 7° posterior; only 8% (n = 2) of patients fell in this range. Rightward deviation toward ventricular septal wall and anterior deviation toward LV anterior freewall are associated with mortalities more so than leftward and posterior deviation. In conclusion, anatomic reconstruction may be a useful preoperative tool to obtain general population and patient-specific alignment for optimal LVAD implantation.

  20. A two-round Delphi study examining consensus of recommended clinical practices for patients with ventricular assist devices as destination therapy.

    Science.gov (United States)

    Chichetti, JoAnne V

    2011-03-01

    To identify the current clinical practices of Medicare-certified facilities offering ventricular assist devices as destination therapy and to attain a consensus of recommended clinical practices across the United States for the management of adults with ventricular assist devices as destination therapy. Sixty ventricular assist device coordinators from Medicare-certified centers were invited to participate in an online, 2-round Delphi survey. The surveys asked whether recommended practices are current practices and whether respondents always/agreed or never/disagreed with performing the recommended practice guidelines. Consensus was defined as 75% agreement. The clinical areas of focus were patient selection, preoperative preparation, postoperative care, infection control, nutrition, and patient discharge preparation. Practices were extracted from the advanced practice guidelines for HeartMate destination therapy and the International Society for Heart and Lung Transplantation's 2006 guidelines for the care of heart transplant candidates. Representing 21 states across the country, the first-round survey had a response rate of 57% (n = 34). The second-round survey had a response rate of 74% (n = 17), representing 28% of the 60 centers. Consensus was obtained for 122 practices. The dimension of patient selection-diagnostic tests and screening had the highest level of consensus (16%, n = 20), and the dimension of postoperative care-intermediate/intensive care unit dimension had the lowest level of consensus (3.3%, n = 4). Survey results identify a consensus of practices for the specific group of ventricular assist device coordinators who responded, but that consensus cannot be generalized to all ventricular assist device facilities. These results can, however, provide a foundation for further research leading to the development of standard-of-care practices for patients with ventricular assist devices as destination therapy.

  1. A Heart for Travel: Travel Health Considerations for Patients with Heart Disease and Cardiac Devices.

    Science.gov (United States)

    Flaherty, G; De Freitas, S

    2016-12-12

    Cardiovascular disease is the leading cause of death in adult international travellers. Patients living with heart disease should receive specific, individualised pre-travel health advice. The purpose of this article is to provide evidence-based advice to physicians who are consulted by travellers with cardiovascular disease. Fitness-to-travel evaluation will often be conducted by the general practitioner but other medical specialists may also be consulted for advice. Patients with chronic medical conditions should purchase travel health insurance. The general pre-travel health consultation addresses food and water safety, insect and animal bite avoidance, malaria chemoprophylaxis, and travel vaccinations. Patients with devices such as cardiac pacemakers should be familiar with how these may be affected by travel. Cardiac medications may cause adverse effects in cold or hot environments, and specific precautions must be followed by anticoagulated travellers. The physician should be aware of how to access medical care abroad, and of the potential for imported tropical diseases in returned travellers.

  2. Fluid removal in acute heart failure: diuretics versus devices.

    Science.gov (United States)

    Krishnamoorthy, Arun; Felker, G Michael

    2014-10-01

    Fluid removal and relief of congestion are central to treatment of acute heart failure. Diuretics have been the decongestive mainstay but their known limitations have led to the exploration of alternative strategies. This review compares diuretics with ultrafiltration and examines the recent evidence evaluating their use. Relevant recent studies are the Diuretic Optimization Strategies Evaluation trial (of diuretics) and the Cardiorenal Rescue Study in Acute Decompensated Heart Failure (of ultrafiltration). The Diuretic Optimization Strategies Evaluation study evaluated strategies of loop diuretic use during acute heart failure (continuous infusion versus intermittent bolus and high dose versus low dose). After 72  h, there was no significant difference with either comparison for the coprimary end points. Patients treated with a high-dose strategy tended to have greater diuresis and more decongestion compared with low-dose therapy, at the cost of transient changes in renal function. The Cardiorenal Rescue Study in Acute Decompensated Heart Failure study showed that in acute heart failure patients with persistent congestion and worsening renal function, ultrafiltration, as compared with a medical therapy, was associated with similar weight loss but greater increase in serum creatinine and more adverse events. Decongestion remains a major challenge in acute heart failure. Although recent studies provide useful data to guide practice, the relatively poor outcomes point to the continued need to identify better strategies for safe and effective decongestion.

  3. Performance of a novel bipolar/monopolar radiofrequency ablation device on the beating heart in an acute porcine model.

    Science.gov (United States)

    Saint, Lindsey L; Lawrance, Christopher P; Okada, Shoichi; Kazui, Toshinobu; Robertson, Jason O; Schuessler, Richard B; Damiano, Ralph J

    2013-01-01

    Although the advent of ablation technology has simplified and shortened surgery for atrial fibrillation, only bipolar clamps have reliably been able to create transmural lesions on the beating heart. Currently, there are no devices capable of reproducibly creating the long linear lesions in the right and left atria needed to perform a Cox-Maze procedure. This study evaluated the performance of a novel suction-assisted radiofrequency device that uses both bipolar and monopolar energy to create lesions from an epicardial approach on the beating heart. Six domestic pigs underwent median sternotomy. A dual bipolar/monopolar radiofrequency ablation device was used to create epicardial linear lesions on the superior and inferior vena cavae, the right and left atrial free walls, and the right and left atrial appendages. The heart was stained with 2,3,5-triphenyl-tetrazolium chloride, and each lesion was cross-sectioned at 5-mm intervals. Lesion depth and transmurality were determined. Transmurality was documented in 94% of all cross sections, and 68% of all ablation lines were transmural along their entire length. Tissue thickness was not different between the transmural and nontransmural cross sections (3.1 ± 1.3 and 3.4 ± 2.1, P = 0.57, respectively), nor was the anatomic location on the heart (P = 0.45 for the distribution). Of the cross sections located at the end of the ablation line, 11% (8/75) were found to be nontransmural, whereas only 4% (8/195) of the cross sections located within the line of ablation were found to be nontransmural (P = 0.04). Logistic regression analysis demonstrated that failure of the device to create transmural lesions was associated with low body temperature (P = 0.006) but not with cardiac output (P = 0.54). This novel device was able to consistently create transmural epicardial lesions on the beating heart, regardless of anatomic location, cardiac output, or tissue thickness. The performance of this device was improved over most

  4. Cardiovascular Implantable Electronic Device Infections in Left Ventricular Assist Device Recipients

    Science.gov (United States)

    Riaz, Talha; Nienaber, Juhsien JC; Baddour, Larry M.; Walker, Randall C.; Park, Soon J.; Sohail, M. Rizwan

    2013-01-01

    Background Most patients with left ventricular assist devices (LVAD) have concomitant cardiovascular implantable electronic devices (CIED). However, clinical presentation and outcome of CIED infection in the setting of LVAD has not been previously described. Methods We retrospectively reviewed 247 patients who underwent LVAD implantation at Mayo Clinic campuses in Minnesota, Arizona and Florida, from January 2005 to December 2011. Demographic and clinical data of patients that met criteria for CIED infection were extracted. Results Of 247 patients with LVADs, 215 (87%) had CIED at the time of LVAD implantation and six (2.8%) subsequently developed CIED infections. Three patients developed CIED lead-related endocarditis and other 3 had pocket infection. All 3 instances of CIED pocket infection were preceded by device generator exchange, while all three patients with CIED lead-related endocarditis had prior LVAD-related infections. Causative pathogens included Pseudomonas aeruginosa (1), coagulase-negative staphylococci (2), methicillin-resistant Staphylococcus aureus (1), a gram-positive bacillus (1), and culture-negative (2). All patients underwent complete CIED removal along with antimicrobial therapy. The 3 patients with CIED lead- related endocarditis and prior LVAD infections received chronic suppressive antibiotic therapy, and one patient had LVAD exchange. All but one remained alive at the last follow-up with a median duration of 15 months (7–46 months) from the time of CIED infection. Conclusion Patients who are receiving LVAD therapy and develop CIED infection should be managed with complete CIED removal. Chronic suppressive antibiotic therapy is warranted in cases that have concomitant LVAD infection. PMID:23998684

  5. Effect of clenbuterol on cardiac and skeletal muscle function during left ventricular assist device support.

    Science.gov (United States)

    George, Isaac; Xydas, Steve; Mancini, Donna M; Lamanca, John; DiTullio, Marco; Marboe, Charles C; Shane, Elizabeth; Schulman, Allison R; Colley, Patrick M; Petrilli, Christopher M; Naka, Yoshifumi; Oz, Mehmet C; Maybaum, Simon

    2006-09-01

    High-dose clenbuterol (a selective beta2-adrenergic agonist) has been proposed to promote myocardial recovery during left ventricular assist device (LVAD) support, but its effects on cardiac and skeletal muscle are largely unknown. Seven subjects with heart failure (5 ischemic, 2 non-ischemic) were started on oral clenbuterol 5 to 46 weeks post-LVAD implantation and up-titrated to daily doses of 720 microg. The following procedures were performed at baseline and after 3 months of therapy: echocardiography at reduced support (4 liters/min); cardiopulmonary exercise testing; body composition analysis; and quadriceps maximal voluntary contraction (MVC). Myocardial histologic analysis was measured at device implantation and explantation. There were no serious adverse events or arrhythmias. Creatine phosphokinase (CPK) was elevated in 4 subjects, with no clinical sequelae. No change in ejection fraction was seen. End-diastolic dimension increased significantly (4.73 +/- 0.67 vs 5.24 +/- 0.66; p clenbuterol. However, clenbuterol therapy increased skeletal muscle mass and strength and prevented the expected decrease in myocyte size during LVAD support. Further study will clarify its potential for cardiac and skeletal muscle recovery.

  6. More than 20 years' experience of left ventricular assist device implantation at a non-transplant Centre.

    Science.gov (United States)

    Holmberg, Erica; Ahn, Henrik; Peterzén, Bengt

    2017-12-01

    Over recent decades implantable left ventricular assist devices (LVAD) have increased the possibility of improved survival in patients with advanced heart failure who also benefit from a better quality of life. The aim of this retrospective survey was to review the clinical results of LVAD implantation at a low-volume non-transplant centre (Linköping, Sweden) between 1993 and 2016. Our aim was also to assess the mortality and morbidity rates associated with implantation of three LVAD versions at our centre, and to compare our results with those from transplant centres. A retrospective cohort study was performed examining the medical records of patients who had a HeartMate(®) (HMI, HMII, HMIII) LVAD implanted as a bridge to heart transplantation (BTT) or as destination therapy (DT) at the University Hospital, Linköping. Our main finding was a survival to heart transplantation rate of 82% among our BTT LVAD patients. The most common adverse event among our patients was infection. A higher frequency of temporary dialysis was seen in the HMII group compared to the HMI group, and the frequency of right ventricular failure was higher in our HMII material. Our data suggests that patients requiring long-term LVAD support can safely have their device implanted and cared for at a non-transplant centre.

  7. Left Ventricular Assist Device Therapy for Destination Therapy: Is Less Invasive Surgery a Safe Alternative?

    Science.gov (United States)

    Rojas, Sebastian V; Hanke, Jasmin S; Avsar, Murat; Ahrens, Philipp R; Deutschmann, Ove; Tümler, Kirstin A; Uribarri, Aitor; Rojas-Hernández, Sara; Sánchez, Pedro L; González-Santos, José M; Haverich, Axel; Schmitto, Jan D

    2017-06-20

    The number of older patients with congestive heart failure has dramatically increased. Because of stagnating cardiac transplantation, there is a need for an alternative therapy, which would solve the problem of insufficient donor organ supply. Left ventricular assist devices (LVADs) have recently become more commonly used as destination therapy (DT). Assuming that older patients show a higher risk-profile for LVAD surgery, it is expected that the increasing use of less invasive surgery (LIS) LVAD implantation will improve postoperative outcomes. Thus, this study aimed to assess the outcomes of LIS-LVAD implantation in DT patients. We performed a prospective analysis of 2-year outcomes in 46 consecutive end-stage heart failure patients older than 60 years, who underwent LVAD implantation (HVAD, HeartWare) for DT in our institution between 2011 and 2013. The patients were divided into 2 groups according to the surgical implantation technique: LIS (n = 20) vs conventional (n = 26). There was no statistically significant difference in 2-year survival rates between the 2 groups, but the LIS group showed a tendency to improved patient outcome in 85.0% vs 69.2% (P = .302). Moreover, the incidence of postoperative bleeding was minor in LIS patients (0% in the LIS group vs 26.9% in the conventional surgery group, P < .05), who also showed lower rates of postoperative extended inotropic support (15.0% in the LIS group vs 46.2% in the conventional surgery group, P < .05). Our data indicate that DT patients with LIS-LVAD implantation showed a lower incidence of postoperative bleeding, a reduced need for inotropic support, and a tendency to lower mortality compared with patients treated with the conventional surgical technique. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  8. Monitoring hemostasis parameters in left ventricular assist device recipients - a preliminary report.

    Science.gov (United States)

    Hudzik, Bartosz; Kaczmarski, Jacek; Pacholewicz, Jerzy; Zakliczyński, Michał; Gąsior, Mariusz; Zembala, Marian

    2016-09-01

    Mechanical circulatory support (MCS) therapy is associated with the improvement of long-term prognosis in patients with end-stage heart failure. For years it has been used as a bridge to transplant. However, more recently it is even being used as a destination therapy. Recently, clinicians have identified common MCS therapy-associated complications: pump thrombosis, bleeding, and hemolysis. These complications are very challenging with regard to both diagnosis and management. To determine time-dependant changes of selected hemostasis/coagulation parameters in patients with end-stage heart failure treated with MCS and antithrombotic therapy. Sixteen patients with end-stage heart failure on left ventricular assist device (LVAD) were followed for 6 weeks (six blood samples for each patient). Every week an extended hemostasis panel was assessed, including activated partial thromboplastin time, prothrombin time, international normalized ratio, von Willebrand factor (vWF) activity, factor VIII activity, fibrinogen level, D-dimer, platelet response to arachidonic acid (ASPI test) and adenosine diphosphate (ADP test), thrombin receptor activating peptide-6 (TRAP test) and collagen (COL test). The study population comprised 16 men. The median time from LVAD implantation was 120 days (100-150 days). During the study period the D-dimer and fibrinogen concentrations were elevated but remained similar throughout all six measurements. Meanwhile factor VIII and vWF activities were elevated in the first two measurements and then subsequently declined. Inhibition of platelet aggregation was greater early after LVAD implantation. During subsequent weeks the inhibition of platelet aggregation was less pronounced. No patient developed any bleeding or thrombo-embolic event during the study period. Patients on MCS therapy demonstrate significant time-dependant changes in hemostasis parameters (both in the coagulation system and platelet aggregation).

  9. Monitoring hemostasis parameters in left ventricular assist device recipients – a preliminary report

    Science.gov (United States)

    Kaczmarski, Jacek; Pacholewicz, Jerzy; Zakliczyński, Michał; Gąsior, Mariusz; Zembala, Marian

    2016-01-01

    Introduction Mechanical circulatory support (MCS) therapy is associated with the improvement of long-term prognosis in patients with end-stage heart failure. For years it has been used as a bridge to transplant. However, more recently it is even being used as a destination therapy. Recently, clinicians have identified common MCS therapy-associated complications: pump thrombosis, bleeding, and hemolysis. These complications are very challenging with regard to both diagnosis and management. Aim To determine time-dependant changes of selected hemostasis/coagulation parameters in patients with end-stage heart failure treated with MCS and antithrombotic therapy. Material and methods Sixteen patients with end-stage heart failure on left ventricular assist device (LVAD) were followed for 6 weeks (six blood samples for each patient). Every week an extended hemostasis panel was assessed, including activated partial thromboplastin time, prothrombin time, international normalized ratio, von Willebrand factor (vWF) activity, factor VIII activity, fibrinogen level, D-dimer, platelet response to arachidonic acid (ASPI test) and adenosine diphosphate (ADP test), thrombin receptor activating peptide-6 (TRAP test) and collagen (COL test). Results The study population comprised 16 men. The median time from LVAD implantation was 120 days (100–150 days). During the study period the D-dimer and fibrinogen concentrations were elevated but remained similar throughout all six measurements. Meanwhile factor VIII and vWF activities were elevated in the first two measurements and then subsequently declined. Inhibition of platelet aggregation was greater early after LVAD implantation. During subsequent weeks the inhibition of platelet aggregation was less pronounced. No patient developed any bleeding or thrombo-embolic event during the study period. Conclusions Patients on MCS therapy demonstrate significant time-dependant changes in hemostasis parameters (both in the coagulation system and

  10. Simulating ideal assistive devices to reduce the metabolic cost of walking with heavy loads.

    Directory of Open Access Journals (Sweden)

    Christopher L Dembia

    Full Text Available Wearable robotic devices can restore and enhance mobility. There is growing interest in designing devices that reduce the metabolic cost of walking; however, designers lack guidelines for which joints to assist and when to provide the assistance. To help address this problem, we used musculoskeletal simulation to predict how hypothetical devices affect muscle activity and metabolic cost when walking with heavy loads. We explored 7 massless devices, each providing unrestricted torque at one degree of freedom in one direction (hip abduction, hip flexion, hip extension, knee flexion, knee extension, ankle plantarflexion, or ankle dorsiflexion. We used the Computed Muscle Control algorithm in OpenSim to find device torque profiles that minimized the sum of squared muscle activations while tracking measured kinematics of loaded walking without assistance. We then examined the metabolic savings provided by each device, the corresponding device torque profiles, and the resulting changes in muscle activity. We found that the hip flexion, knee flexion, and hip abduction devices provided greater metabolic savings than the ankle plantarflexion device. The hip abduction device had the greatest ratio of metabolic savings to peak instantaneous positive device power, suggesting that frontal-plane hip assistance may be an efficient way to reduce metabolic cost. Overall, the device torque profiles generally differed from the corresponding net joint moment generated by muscles without assistance, and occasionally exceeded the net joint moment to reduce muscle activity at other degrees of freedom. Many devices affected the activity of muscles elsewhere in the limb; for example, the hip flexion device affected muscles that span the ankle joint. Our results may help experimentalists decide which joint motions to target when building devices and can provide intuition for how devices may interact with the musculoskeletal system. The simulations are freely available

  11. Simulating ideal assistive devices to reduce the metabolic cost of walking with heavy loads

    Science.gov (United States)

    Silder, Amy; Uchida, Thomas K.; Hicks, Jennifer L.; Delp, Scott L.

    2017-01-01

    Wearable robotic devices can restore and enhance mobility. There is growing interest in designing devices that reduce the metabolic cost of walking; however, designers lack guidelines for which joints to assist and when to provide the assistance. To help address this problem, we used musculoskeletal simulation to predict how hypothetical devices affect muscle activity and metabolic cost when walking with heavy loads. We explored 7 massless devices, each providing unrestricted torque at one degree of freedom in one direction (hip abduction, hip flexion, hip extension, knee flexion, knee extension, ankle plantarflexion, or ankle dorsiflexion). We used the Computed Muscle Control algorithm in OpenSim to find device torque profiles that minimized the sum of squared muscle activations while tracking measured kinematics of loaded walking without assistance. We then examined the metabolic savings provided by each device, the corresponding device torque profiles, and the resulting changes in muscle activity. We found that the hip flexion, knee flexion, and hip abduction devices provided greater metabolic savings than the ankle plantarflexion device. The hip abduction device had the greatest ratio of metabolic savings to peak instantaneous positive device power, suggesting that frontal-plane hip assistance may be an efficient way to reduce metabolic cost. Overall, the device torque profiles generally differed from the corresponding net joint moment generated by muscles without assistance, and occasionally exceeded the net joint moment to reduce muscle activity at other degrees of freedom. Many devices affected the activity of muscles elsewhere in the limb; for example, the hip flexion device affected muscles that span the ankle joint. Our results may help experimentalists decide which joint motions to target when building devices and can provide intuition for how devices may interact with the musculoskeletal system. The simulations are freely available online, allowing

  12. Heart motion uncertainty compensation prediction method for robot assisted beating heart surgery - Master-slave Kalman Filters approach.

    Science.gov (United States)

    Liang, Fan; Yu, Yang; Cui, Shigang; Zhao, Li; Wu, Xingli

    2014-05-01

    Robot Assisted Coronary Artery Bypass Graft (CABG) allows the heart keep beating in the surgery by actively eliminating the relative motion between point of interest (POI) on the heart surface and surgical tool. The inherited nonlinear and diverse nature of beating heart motion gives a huge obstacle for the robot to meet the demanding tracking control requirements. In this paper, we novelty propose a Master-slave Kalman Filter based on beating heart motion Nonlinear Adaptive Prediction (NAP) algorithm. In the study, we describe the beating heart motion as the combination of nonlinearity relating mathematics part and uncertainty relating non-mathematics part. Specifically, first, we model the nonlinearity of the heart motion via quadratic modulated sinusoids and estimate it by a Master Kalman Filter. Second, we involve the uncertainty heart motion by adaptively change the covariance of the process noise through the slave Kalman Filter. We conduct comparative experiments to evaluate the proposed approach with four distinguished datasets. The results indicate that the new approach reduces prediction errors by at least 30 μm. Moreover, the new approach performs well in robustness test, in which two kinds of arrhythmia datasets from MIT-BIH arrhythmia database are assessed.

  13. Simulating Ideal Assistive Devices to Reduce the Metabolic Cost of Running.

    Directory of Open Access Journals (Sweden)

    Thomas K Uchida

    Full Text Available Tools have been used for millions of years to augment the capabilities of the human body, allowing us to accomplish tasks that would otherwise be difficult or impossible. Powered exoskeletons and other assistive devices are sophisticated modern tools that have restored bipedal locomotion in individuals with paraplegia and have endowed unimpaired individuals with superhuman strength. Despite these successes, designing assistive devices that reduce energy consumption during running remains a substantial challenge, in part because these devices disrupt the dynamics of a complex, finely tuned biological system. Furthermore, designers have hitherto relied primarily on experiments, which cannot report muscle-level energy consumption and are fraught with practical challenges. In this study, we use OpenSim to generate muscle-driven simulations of 10 human subjects running at 2 and 5 m/s. We then add ideal, massless assistive devices to our simulations and examine the predicted changes in muscle recruitment patterns and metabolic power consumption. Our simulations suggest that an assistive device should not necessarily apply the net joint moment generated by muscles during unassisted running, and an assistive device can reduce the activity of muscles that do not cross the assisted joint. Our results corroborate and suggest biomechanical explanations for similar effects observed by experimentalists, and can be used to form hypotheses for future experimental studies. The models, simulations, and software used in this study are freely available at simtk.org and can provide insight into assistive device design that complements experimental approaches.

  14. Treatment of device thrombus in the HeartWare HVAD: Success and outcomes depend significantly on the initial treatment strategy.

    Science.gov (United States)

    Stulak, John M; Dunlay, Shannon M; Sharma, Shashank; Haglund, Nicholas A; Davis, Mary Beth; Cowger, Jennifer; Shah, Palak; Masood, Faraz; Aaronson, Keith D; Pagani, Francis D; Maltais, Simon

    2015-12-01

    Pump thrombosis is a major adverse event in patients supported with a left ventricular assist device (LVAD). Treatment approaches include device exchange, lytic therapy, or augmentation of anticoagulation or antiplatelet therapy. The optimal strategy in the HeartWare HVAD Ventricular Assist System (HeartWare, Framingham, MA) is uncertain, and because few large studies have examined differing treatment outcomes, we have reviewed findings from the Mechanical Circulatory Support Research Network registry. Between March 2009 and August 2014, 175 patients (133 male) underwent implantation of the HeartWare HVAD at institutions that comprise the Mechanical Circulatory Support Research Network. Median age at implant was 59 years (range, 18-76 years). Follow-up was available in all patients for a median of 6 months (maximum, 61 months) and for a total of 163 patient-years of support. There were 36 pump thromboses (using Interagency Registry for Mechanically Assisted Circulatory Support criteria) in 21 patients for a total event rate of 0.22 events/patient-year of support; 13 patients had 1 event, 4 had 2, 2 had 3, 1 had 4, and 1 had 5. The median time to the first thrombosis was 6.4 months, and to each subsequent thrombosis was 4, 3, 2, and 2 months, respectively. Primary treatment success was defined as the patient remaining alive and within the first 30 days of the initial treatment be free from stroke, recurrence of pump thrombosis, device exchange, or urgent transplantation (United Network of Organ Sharing Status 1A). Medical treatment was defined as tissue plasminogen activator, heparin plus glycoprotein IIb/IIIa inhibitor, or heparin alone, not followed by surgical treatment within 72 hours. Initial medical treatment was used in 29 episodes (tissue plasminogen activator in 24, heparin alone in 4, and heparin plus glycoprotein IIb/IIIa in 1) and surgical (device exchange) in 7. Medical treatment was successful in 14 of 29 episodes (48%). Complications of medical

  15. Heart-pulse Biofeedback in Playful Exercise using a Wearable device and Modular Interactive Tiles

    DEFF Research Database (Denmark)

    Shimokakimoto, Tomoya; Lund, Henrik Hautop; Suzuki, Kenji

    2014-01-01

    interactive tiles. The system consists of a wearable device that measures heart-pulse via ear-mounted sensor, and modular interactive tiles which are used for physical rehabilitation exercise through playing a game. The wearable devise enables detection of heart pulse in real-time and therefore provides heart...... beat rate during playful activities, even if the heart pulse wave have motion artifacts. The tiles are designed to build flexible structures and to provide immediate feedback based on the users’ physical interaction with the tiles. We combine the two systems to provide users with heart pulse...... biofeedback in playful exercise. We show that using the developed system it is possible for the users to regulate the exercise intensity on their own with biofeedback, and also possible to analyze exercise activity using number of steps on the tiles and heart beat rate....

  16. Design and Development of a Miniaturized Percutaneously Deployable Wireless Left Ventricular Assist Device: Early Prototypes and Feasibility Testing.

    Science.gov (United States)

    Letzen, Brian; Park, Jiheum; Tuzun, Zeynep; Bonde, Pramod

    2017-09-21

    The current left ventricular assist devices (LVADs) are limited by a highly invasive implantation procedure in a severely unstable group of advanced heart failure patients. Additionally, the current transcutaneous power drive line acts as a nidus for infection resulting in significant morbidity and mortality. In an effort to decrease this invasiveness and eliminate drive line complications, we have conceived a wireless miniaturized percutaneous LVAD, capable of being delivered endovascularly with a tether-free operation. The system obviates the need for a transcutaneous fluid purge line required in existing temporary devices by utilizing an incorporated magnetically coupled impeller for a complete seal. The objective of this article was to demonstrate early development and proof-of-concept feasibility testing to serve as the groundwork for future formalized device development. Five early prototypes were designed and constructed to iteratively minimize the pump size and improve fluid dynamic performance. Various magnetic coupling configurations were tested. Using SolidWorks and ANSYS software for modeling and simulation, several geometric parameters were varied. HQ curves were constructed from preliminary in vitro testing to characterize the pump performance. Bench top tests showed no-slip magnetic coupling of the impeller to the driveshaft up to the current limit of the motor. The pump power requirements were tested in vitro and were within the appropriate range for powering via a wireless energy transfer system. Our results demonstrate the proof-of-concept feasibility of a novel endovascular cardiac assist device with the potential to eventually offer patients an untethered, minimally invasive support.

  17. Model for end-stage liver disease predicts right ventricular failure in patients with left ventricular assist devices.

    Science.gov (United States)

    Yost, Gardner L; Coyle, Laura; Bhat, Geetha; Tatooles, Antone J

    2016-03-01

    High rates of right ventricular failure continue to affect postoperative outcomes in patients implanted with left ventricular assist devices (LVADs). Development of right ventricular failure and implantation with right ventricular assist devices is known to be associated with significantly increased mortality. The model for end-stage liver disease (MELD) score is an effective means of evaluating liver dysfunction. We investigated the prognostic utility of postoperative MELD on post-LVAD implantation outcomes. MELD scores, demographic data, and outcomes including length of stay, survival, and postoperative right ventricular failure were collected for 256 patients implanted with continuous flow LVADs. Regression and Kaplan-Meier analyses were used to investigate the relationship between MELD and all outcomes. Increased MELD score was found to be an independent predictor of both right heart failure and necessity for RVAD implantation (OR 1.097, CI 1.040-1.158, p = 0.001; OR 1.121, CI 1.015, p = 0.024, respectively). Patients with RV failure and who underwent RVAD implantation had reduced postoperative survival compared to patients with RV dysfunction (no RV failure = 651.4 ± 609.8 days, RV failure = 392.6 ± 444.8 days, RVAD = 89.3 ± 72.8 days; p < 0.001). In conclusion, MELD can be used to reliably predict postoperative right heart failure and the necessity for RVAD implantation. Those patients with RV failure and RVADs experience significantly increased postoperative mortality compared to those without RV dysfunction.

  18. The mechanism of action of the vacuum-assisted closure device.

    Science.gov (United States)

    Scherer, Sandra Saja; Pietramaggiori, Giorgio; Mathews, Jasmine C; Prsa, Michael J; Huang, Sui; Orgill, Dennis P

    2008-09-01

    The vacuum-assisted closure device is widely used clinically, yet its mechanisms of action are incompletely understood. In this study, the authors designed a partially splinted full-thickness murine vacuum-assisted closure model to better understand the mechanism of action of the vacuum-assisted closure device. Full-thickness wounds (n = 10 per group) were excised in diabetic mice and treated with the vacuum-assisted closure device or its isolated components: an occlusive dressing, subatmospheric pressure at 125 mmHg (suction), and a polyurethane foam without and with downward compression. Results were quantified with a two-dimensional immunohistochemical staging system based on blood vessel density (CD31) and cell proliferation (Ki67) 7 days after wounding. Microscopic strain was measured by fixing in situ all dressing modalities. Wounds exposed to polyurethane foam in compressed and uncompressed dressings or to the vacuum-assisted closure device showed a 2-fold increase in vascularity compared with the occlusive dressing group (p vacuum-assisted closure device in addition stimulated cell proliferation, with up to 82 percent Ki67-positive nuclei, compared with the other groups. Direct measurements of wound surface deformations showed significant microstrains in the vacuum-assisted closure and foam in compressed dressing groups (60 percent and 16 percent, respectively) compared with all other groups. These data provide profound insights into the mechanism of action of the vacuum-assisted closure device, providing an explanation for the increases in wound bed vascularity and cell proliferation based on its components. Results suggest that the vascular response is related to the polyurethane foam, whereas tissue strains induced by the vacuum-assisted closure device stimulated cell proliferation.

  19. Heart transplantation.

    Science.gov (United States)

    Cheng, Allen; Slaughter, Mark S

    2014-08-01

    Heart failure remains a major global problem with approximately 6 million individuals suffering from heart failure in the United States alone. The surgical technique of heart transplantation, popularized by Dr. Norman Shumway, has led to its success and currently remains the best treatment options for patients with end-stage. However, with the continued limitation of donor organs and the rapid development of ventricular assist device technology, the number of patients bridged to transplant with mechanical circulatory support has increased significantly. This has created some new technical challenges for heart transplantation. Therefore, it is now important to be familiar with multiple new technical challenges associated with the surgical techniques of heart transplantation with an ultimate goal in reducing donor heart ischemic time, recipient cardiopulmonary bypass time and post-operative complications. In this review, we described our technique of heart transplantation including the timing of the operation, recipient cardiectomy and donor heart implantation.

  20. Analysis of Contemporary Methods for Designing Rotary Type Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    E. P. Banin

    2015-01-01

    Full Text Available The research object is inlet apparatus of ventricular assist device, namely inlet cannula and straightener.The purpose of the study is to reveal features of blood flow in inlet apparatus of ventricular assist device. The mathematical modeling is carried out by computational fluid dynamics analysis in a stationary setting.The first part of study concerns the analysis of existing approaches to the numerical and experimental studies in designing the ventricular assist devices of rotary type. It reveals the features of each approach for their further application in practice. The article presents an original design of developed hydraulic test bench to verify the results of mathematical modeling. Analysis of foreign authors’ studies showed that there is no enough attention paid to design of the adjacent pump assemblies of ventricular assist device. The second part of study considers direct mathematical modeling of input apparatus of ventricular assist device. The study examined straightener with three or four blades. Mathematical modeling has revealed the presence of potentially dangerous stagnation zones and essential asymmetry of the outlet flow from the input unit. The found features must be taken in consideration in designing the ventricular assist device pumps. In the future we plan to use obtained data to create a parametric model of the rotor and the diffuser considering the abovementioned features.

  1. Invasive device-related infections after heart surgery.

    Science.gov (United States)

    Álvarez Lerma, F; Carrasco, M; Otal, J J; Palomar, M; Olaechea, P; Peris, X; Iglesias, L; Martínez Pellus, A; Arenzana, A; Ballesteros, J C

    2013-12-01

    To analyze postoperative infections in critically ill patients undergoing heart surgery. Intensive care units (ICUs). An observational, prospective, multicenter study was carried out. Patients in the postoperative period of heart surgery admitted to the ICU and included in the ENVIN-HELICS registry between 2005 and 2011. Mechanical ventilation associated pneumonia (MVP), urinary catheter-related infection (UCI), primary bacteremia (PB), PB related to vascular catheters (PB-VC) and secondary bacteremia. Of a total of 97,692 patients included in the study, 9089 (9.3%) had undergone heart surgery. In 440 patients (4.8%), one or more infections were recorded. Infection rates were 9.94 episodes of MVP per 1000 days of mechanical ventilation, 3.4 episodes of UCI per 1000 days of urinary catheterization, 3.10 episodes of BP-VC per 1000 days of central venous catheter, and 1.84 episodes of secondary bacteremia per 1000 days of ICU stay. Statistically significant risk factors for infection were ICU stay (odds ratio [OR] 1.18, 95%CI 1.16-1.20), APACHE II upon admission to the ICU (OR 1.05, 95%CI 1.03-1.07), emergency surgery (OR 1.67, 95%CI 1.13-2.47), previous antibiotic treatment (OR 1.38, 95%CI 1.04-1.83), and previous colonization by Pseudomonas aeruginosa (OR 18.25, 95%CI 3.74-89.06) or extended spectrum beta-lactamase producing enterobacteria (OR 16.97, 95%CI 5.4-53.2). The overall ICU mortality rate was 4.1% (32.2% in patients who developed one or more infections and 2.9% in uninfected patients) (P < .001). Of the patients included in the ENVIN-HELICS registry, 9.3% were postoperative heart surgery patients. The overall mortality was low but increased significantly in patients who developed one or more infection episodes. Copyright © 2012 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  2. Mobile Learning as Alternative to Assistive Technology Devices for Special Needs Students

    Science.gov (United States)

    Ismaili, Jalal; Ibrahimi, El Houcine Ouazzani

    2017-01-01

    Assistive Technology (AT) revolutionized the process of learning for special needs students during the past three decades. Thanks to this technology, accessibility and educational inclusion became attainable more than any time in the history of special education. Meanwhile, assistive technology devices remain unreachable for a large number of…

  3. The Importance of the Management of Infectious Complications for Patients with Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Michinari Hieda

    2015-08-01

    Full Text Available A left ventricular assist device (LVAD therapy is the viable option for patients with advanced heart failure as a bridge to transplantation, bridge to recovery, or destination therapy. Although application of LVAD support has become a standard option, serious complications or adverse events related with LVAD remain a concern. LVAD-related infection including driveline infection (DLI and bloodstream infection (BSI is one of the serious clinical matters for LVAD patients, and especially BSI leads to the high incidence of mortality. The LVAD-related infections negatively impact patient’s quality of life. Therefore, control of infection is one of the primary goals of management in LVAD patients. Several efforts including early and appropriate intervention including antibiotics and wound care may contribute to avert the progress into BSI from localized DLI. Particularly, there are clinical secrets in how to use antibiotics and how to treat wound care in LVAD patients. The rational way of thinking for wound care will be introduced in this review.

  4. Transient and quasi-steady computational fluid dynamics study of a left ventricular assist device.

    Science.gov (United States)

    Song, Xinwei; Throckmorton, Amy L; Wood, Houston G; Allaire, Paul E; Olsen, Don B

    2004-01-01

    The HeartQuest continuous flow left ventricle assist device (LVAD) with a magnetically levitated impeller operates under highly transient flow conditions. Due to insertion of the in-flow cannula into the apex of the left ventricle, the inlet flow rate is transient because of ventricular contraction, and the pump's asymmetric circumferential configuration with five rotating blades forces blood intermittently through the pump to the great arteries. These two transient conditions correspond to time varying boundary conditions and transient rotational sliding interfaces in computational fluid dynamics (CFD). CFD was used to investigate the pump's performance under these dynamic flow conditions. A quasi-steady analysis was also conducted to evaluate the difference between the steady and transient analyses and demonstrate the significance of transient analysis, especially for transient rotational sliding interfaces transient simulations. This transient flow analysis can be applied generally in the design process of LVADs; it provides more reliable fluid forces and moments on the impeller for successful design of the magnetic suspension system and motor.

  5. The Spectrum of General Surgery Interventions in Pediatric Patients with Ventricular Assist Devices.

    Science.gov (United States)

    Kamel, Fady; Buchholz, Holger; Dicken, Bryan; Conway, Jennifer

    2017-06-13

    Ventricular assist devices (VADs) have positively impacted the management of heart failure. However, they come with a range of complications. Although general surgical complications have been assessed in adults with VADs, there is no study to date that has assessed general surgery intervention in the pediatric population. Fifty-two patients who received VADs from 2005 to 2015 at the Stollery Children's Hospital were assessed for general surgery intervention and anticoagulation status at the time of intervention. Eighteen patients (35%) had general surgery intervention; there were 21 nonemergency procedures and six emergency procedures performed. For nonemergency procedures, 89% of patients had anticoagulation held within 24 hours of surgery and 84% had anticoagulation resumed within 4 hours postoperatively. Antiplatelet therapy was not held perioperatively. In both emergency and nonemergency procedures, anticoagulation status was not a factor in the success of the procedure. This study shows that it is safe to have general surgery intervention on the same admission as a VAD implant provided an appropriate interdisciplinary healthcare team is involved with the perioperative management of the patient.

  6. Thresholds of physical activity and life expectancy for patients considering destination ventricular assist devices.

    Science.gov (United States)

    Stewart, Garrick C; Brooks, Kimberly; Pratibhu, Parakash P; Tsang, Sui W; Semigran, Marc J; Smith, Colleen M; Saniuk, Catherine; Camuso, Janice M; Fang, James C; Mudge, Gilbert H; Couper, Gregory S; Baughman, Kenneth L; Stevenson, Lynne W

    2009-09-01

    Current implantable left ventricular assist devices (LVAD) improve survival and function for patients with very late stage heart failure (HF) but may also offer benefit before inotrope dependence. Debate continues about selection of HF patients for LVAD therapy. We sought to determine what level of personal risk and disability HF patients thought would warrant LVAD therapy. The study included 105 patients with symptomatic HF and an LV ejection fraction (EF) trade-off utility, and patient-assessed functional score were determined. Participants (mean age, 58 years) had an LVEF of 21%. The median duration of HF was 5 years, and 65% had a primary prevention implantable cardioverter defibrillator. Presented with a scenario of bed-ridden HF, 81% stated they would definitely or probably want an LVAD; 50% would consider LVAD to prolong survival if HF survival were predicted to be dress without stopping. Anticipated thresholds did not differ by NYHA class, time trade-off, or functional score. Patient thresholds for LVAD insertion parallel objective survival and functional data. HF patients would be receptive to referral for discussion of LVAD by the time expected mortality is within 6 to 12 months and activity remains limited to less than 1 block.

  7. Analysis of a fatal left ventricular assist device infection: a case report and discussion

    Directory of Open Access Journals (Sweden)

    Gerstein NS

    2015-01-01

    Full Text Available No abstract available. Article truncated at 150 words. Introduction: Left ventricular assist device (VAD therapy is an increasingly utilized treatment as a bridge to heart transplantation or as long-term destination therapy. Recent reports show there is a 22% - 32% incidence of VAD-associated infections with staphylococci and nosocomial gram-negative bacilli being the most common causative organisms (1,2. These organisms are often found in intensive care units, where they have the highest proportion of resistance, thus exposing already critically ill patients to the possibility of resistant organism VAD-associated infections (3. Mortality rates exceed 60% when sepsis develops in a patient with a continuous flow left VAD and infection is the number one cause of death in those awaiting cardiac transplantation (4,5. With continued left VAD use clinicians will likely see multidrug-resistant (MDR or even pandrug-resistant organism VAD-associated infections. Clinicians need to be prepared to manage such an intimidating entity. Case Report: We report a case of a 25 year-old ...

  8. Initial In Vivo Evaluation of a Novel Left Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Guanghui Wu

    2015-01-01

    Full Text Available The aim of the study was to use the ovine model to evaluate the hemocompatibility and end-organ effects of a newly developed magnetic suspension centrifugal left ventricular assist device (LVAD by CH Biomedical Inc., Jiangsu, China. The LVADs were implanted in 6 healthy sheep, where inflow was inserted into the left ventricular apex and outflow was anastomosed to the descending aorta. All sheep received anticoagulation and antiaggregation therapy during the study. Hematologic and biochemical tests were performed to evaluate anemia, hepatorenal function, and the extent of hemolysis. The experiments lasted for up to 30 days on the beating hearts. All sheep were humanely killed at the termination of the experiments, and the end-organs were examined macroscopically and histopathologically. Autopsy was performed in all animals and there was no thrombus formation observed inside the pump. The pump’s inflow and outflow conduits were also free of thrombus. Hematologic and biochemical test results were within normal limits during the study period. Postmortem examination of the explanted organs revealed no evidence of ischemia or infarction. Based on the in vivo study, this LVAD is suitable for implantation and can provide efficient support with good biocompatibility. The encouraging results in this study suggest that it is feasible to evaluate the device’s long-term durability and stability.

  9. On the degradation of field-plate assisted RESURF power devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Dhar, S.; Ferrara, A.; Heringa, A.; Hueting, Raymond Josephus Engelbart; Koops, G.E.J.; Salm, Cora; Schmitz, Jurriaan

    2012-01-01

    Hot-carrier degradation phenomena in field-plate assisted reduced surface field (RESURF) devices caused by high voltage off- and on-state stressing have been investigated. The device I-V characteristics are analyzed and modeled in detail. It is shown that via noninvasive low-voltage leakage

  10. Impact of interface charge on the electrostatics of field-plate assisted RESURF devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Ferrara, A.; Heringa, A.; Steeneken, P.G.; Hueting, Raymond Josephus Engelbart

    2014-01-01

    A systematic study on the effects of arbitrary parasitic charge profiles, such as trapped or fixed charge, on the 2-D potential distribution in the drain extension of reverse-biased field-plate-assisted reduced surface field (RESURF) devices is presented. Using TCAD device simulations and analytical

  11. Non-invasive control interfaces for intention detection in active movement-assistive devices

    NARCIS (Netherlands)

    Lobo-Prat, J.; Kooren, P.N.; Stienen, A.H.A.; Herder, J.L.; Koopman, B.F.J.M.; Veltink, P.H.

    2014-01-01

    Active movement-assistive devices aim to increase the quality of life for patients with neuromusculoskeletal disorders. This technology requires interaction between the user and the device through a control interface that detects the user’s movement intention. Researchers have explored a wide

  12. The use of Computer Assisted Language Learning (CALL) Devices ...

    African Journals Online (AJOL)

    Computer-Assisted Language Learning (CALL) is a relatively new and rapidly evolving academic field that explores the role of information and communication technologies in language learning and teaching. It has rapidly developed over the last forty years. This development can be categorized into three distinct phases: ...

  13. Metabolic volume performs better than SUVmax in the detection of left ventricular assist device driveline infection.

    Science.gov (United States)

    Avramovic, Nemanja; Dell'Aquila, Angelo Maria; Weckesser, Matthias; Milankovic, Danka; Vrachimis, Alexis; Sindermann, Jürgen R; Wenning, Christian

    2017-05-25

    A continuous-flow left ventricular assist device (LVAD) is a new and highly promising therapy in supporting end-stage heart failure patients, either bridging them to heart transplantation or as a destination therapy. Infection is one of the major complications associated with LVAD implants. (18)F-FDG PET/CT has already been shown to be useful in the detection of LVAD infection. The goal of this study was to compare the diagnostic accuracy of different PET analysis techniques (visual grading versus SUVmax and metabolic volume). We retrospectively analyzed 48 patients with implanted LVAD who underwent an (18)F-FDG PET/CT that were either suspected to have a driveline or device infection or inflammation of unknown origin. PET/CT was analyzed qualitatively (visual grading) and quantitatively (SUVmax and metabolic volume) and matched to the final clinical diagnosis concerning driveline infection. The final diagnosis (standard of reference) was made at the end of clinically recorded follow-up or transplantation and included microbiological cultures of the driveline exit site and/or surgical samples, and clinical signs of infection despite negative cultures as well as recurrence of symptoms. Sensitivity, specificity, positive and negative predictive value were 87.5%, 79%, 81% and 86% for visual score, 87.5%, 87.5%, 87.5% and 87.5% for SUVmax and 96%, 87.5%, 88.5%, 95.5% for metabolic volume, respectively. ROC analysis revealed an AUC of .929 for SUVmax and .969 for metabolic volume. Both SUVmax and metabolic volume had a high detection rate of patients with driveline infection (21/24 = 91.5% true positive vs. 23/26 = 88.5% true positive, respectively). However, metabolic volume detected more patients without any infection correctly (1/22 = 4.5% false negative vs. 3/24 = 12.5% false negative). (18)F-FDG PET/CT is a valuable tool for the diagnosis of LVAD driveline infection with high diagnostic accuracy. Particularly the use of the metabolic volume yields very high

  14. Metabolic volume performs better than SUVmax in the detection of left ventricular assist device driveline infection

    Energy Technology Data Exchange (ETDEWEB)

    Avramovic, Nemanja; Weckesser, Matthias; Milankovic, Danka; Vrachimis, Alexis; Wenning, Christian [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Dell' Aquila, Angelo Maria; Sindermann, Juergen R. [University Hospital Muenster, Department of Cardiac Surgery, Muenster (Germany)

    2017-10-15

    A continuous-flow left ventricular assist device (LVAD) is a new and highly promising therapy in supporting end-stage heart failure patients, either bridging them to heart transplantation or as a destination therapy. Infection is one of the major complications associated with LVAD implants. {sup 18}F-FDG PET/CT has already been shown to be useful in the detection of LVAD infection. The goal of this study was to compare the diagnostic accuracy of different PET analysis techniques (visual grading versus SUVmax and metabolic volume). We retrospectively analyzed 48 patients with implanted LVAD who underwent an {sup 18}F-FDG PET/CT that were either suspected to have a driveline or device infection or inflammation of unknown origin. PET/CT was analyzed qualitatively (visual grading) and quantitatively (SUVmax and metabolic volume) and matched to the final clinical diagnosis concerning driveline infection. The final diagnosis (standard of reference) was made at the end of clinically recorded follow-up or transplantation and included microbiological cultures of the driveline exit site and/or surgical samples, and clinical signs of infection despite negative cultures as well as recurrence of symptoms. Sensitivity, specificity, positive and negative predictive value were 87.5%, 79%, 81% and 86% for visual score, 87.5%, 87.5%, 87.5% and 87.5% for SUVmax and 96%, 87.5%, 88.5%, 95.5% for metabolic volume, respectively. ROC analysis revealed an AUC of.929 for SUVmax and.969 for metabolic volume. Both SUVmax and metabolic volume had a high detection rate of patients with driveline infection (21/24 = 91.5% true positive vs. 23/26 = 88.5% true positive, respectively). However, metabolic volume detected more patients without any infection correctly (1/22 = 4.5% false negative vs. 3/24 = 12.5% false negative). {sup 18}F-FDG PET/CT is a valuable tool for the diagnosis of LVAD driveline infection with high diagnostic accuracy. Particularly the use of the metabolic volume yields very

  15. User assistance for multitasking with interruptions on a mobile device

    NARCIS (Netherlands)

    Nagata, S.F.

    2006-01-01

    Issues users have with use of the web on a mobile device can be attributed to difficulties with the mobile interface. A major challenge that we address is improving the user experience for handling of interruptions and multitasking when using the web in a mobile context. The usability issues with a

  16. User Assistance for Multitasking with Interruptions on a Mobile Device

    NARCIS (Netherlands)

    Nagata, S.F.

    2006-01-01

    Issues users have with use of the web on a mobile device can be attributed to difficulties with the mobile interface. A major challenge that we address is improving the user experience for handling of interruptions and multitasking when using the web in a mobile context. The usability issues with a

  17. 78 FR 34922 - Definition of Auditory Assistance Device

    Science.gov (United States)

    2013-06-11

    ... production and marketing, and introduce more competition for such devices. The Commission decided that this... converted from analog to digital transmissions. The Commission also noted that it had previously sought comment on measures to improve digital TV reception for consumers on VHF channels and encourage...

  18. Needs for mobility devices, home modifications and personal assistance among Canadians with disabilities.

    Science.gov (United States)

    Giesbrecht, Edward M; Smith, Emma M; Mortenson, W Ben; Miller, William C

    2017-08-16

    People with disabilities often require assistive devices, modifications to their home environment, and physical assistance to facilitate mobility. This study examines self-reported met and unmet needs of people with disabilities who use wheeled mobility devices, compared with non-users. The 2012 Canadian Survey on Disability followed up with 45,442 individuals who reported a disability on the 2011 National Household Survey, and obtained a 75% response rate. Descriptive statistics with variance estimates and 95% confidence intervals were used to compare wheeled mobility device users and non-users. Nearly 10% of wheeled mobility device users identified an unmet need for an additional mobility device. Compared with non-users, they were twice as likely to modify their home with a ramp and three times as likely to install a lift. The prevalence of unmet need for each type of residence adaptation among wheeled mobility device users was at least double that of non-users. Wheeled mobility device users received assistance with an average of 4.4 activities, compared with 2.0 for non-users, and reported an average of 1.9 activities for which assistance was needed but not received. About one in three relied on paid assistance; for 14% of those who paid for assistance, out-of-pocket expenses amounted to $10,000 or more annually, compared with 2% among non-users. Wheeled mobility device users reported a higher prevalence of met and unmet needs for residence modifications than did non-users. They required help with more activities of life on a more frequent basis, with greater dependence on paid individuals, resulting in higher out-of-pocket expenses. Power and manual wheelchair users reported greater needs than did mobility scooter users.

  19. Stretchable Materials for Robust Soft Actuators towards Assistive Wearable Devices

    Science.gov (United States)

    Agarwal, Gunjan; Besuchet, Nicolas; Audergon, Basile; Paik, Jamie

    2016-09-01

    Soft actuators made from elastomeric active materials can find widespread potential implementation in a variety of applications ranging from assistive wearable technologies targeted at biomedical rehabilitation or assistance with activities of daily living, bioinspired and biomimetic systems, to gripping and manipulating fragile objects, and adaptable locomotion. In this manuscript, we propose a novel two-component soft actuator design and design tool that produces actuators targeted towards these applications with enhanced mechanical performance and manufacturability. Our numerical models developed using the finite element method can predict the actuator behavior at large mechanical strains to allow efficient design iterations for system optimization. Based on two distinctive actuator prototypes’ (linear and bending actuators) experimental results that include free displacement and blocked-forces, we have validated the efficacy of the numerical models. The presented extensive investigation of mechanical performance for soft actuators with varying geometric parameters demonstrates the practical application of the design tool, and the robustness of the actuator hardware design, towards diverse soft robotic systems for a wide set of assistive wearable technologies, including replicating the motion of several parts of the human body.

  20. Experimental testing of a new left ventricular assist device--the microdiagonal blood pump.

    Science.gov (United States)

    Christiansen, Stefan; Demircan, Lütfü; Kwant, Paul B; Akdis, Mustafa; Rex, Steffen; Buhre, Wolfgang; Langebartels, Georg; Kuruc, Norbert; Nikolin, Stefan; Reul, Helmut; Autschbach, Rüdiger

    2004-01-01

    All existing ventricular assist devices are associated with a considerable number of serious complications. This article reports on the first animal tests with a newly developed microdiagonal blood pump (MDP). Six adult female sheep weighing 80 to 90 kg underwent implantation of the microdiagonal blood pump. The inflow and outflow conduits were anastomosed to the left atrium and the descending aorta. Pump flow was adjusted to 2-3 L/minute. Hemodynamic and echocardiographic data, as well as blood samples, were measured over the entire test period of 7 days. All internal organs and the pump were explanted for thorough examination at the end of the trial. Mean arterial (range 88.5 +/- 13.1-103.7 +/- 10.7 mm Hg) and mean pulmonary arterial (18.3 +/- 2.7-21.6 +/- 20.5 mm Hg) pressures, as well as the pulmonary capillary wedge pressure (14.2 +/- 3.0 - 16.6 +/- 4.0 mm Hg), remained stable during the whole test period. Cardiac output (4.9 +/- 0.7 --> 3.2 +/- 0.5 L/minute) decreased postoperatively caused by partial unloading of the heart. Left ventricular end diastolic (4.1 +/- 0.5 --> 3.6 +/- 0.3 cm) and end systolic (3.2 +/- 0.4 --> 2.8 +/- 0.5 cm) diameters, as well as the ejection fraction (57 +/- 9 --> 42 +/- 5%), decreased after MDP implantation and did not change during the test period. Mean number of platelets (428 +/- 54 --> 286 +/- 66 x 10(3)/microL) and hemoglobin (9.8 +/- 1.3 --> 6.3 +/- 0.8 g/dL) decreased perioperatively because of surgical reasons and increased continuously in the postoperative course (platelet count and hemoglobin on day 7:441 +/- 74 x 10(3)/microL and 7.2 +/- 1.1 g/dL, respectively). Free hemoglobin was not enhanced in the postoperative course (mean value during the test period: 18.8 mmoL/L). Histologic examination of the organs did not demonstrate any infarctions of internal organs other than typical operative sequelae such as chronic pericarditis and some degree of atelectasis of the left lungs. These results demonstrate that the

  1. Percutaneous Implantation of A Parachute Device For Treatment of Ischemic Heart Failure

    Energy Technology Data Exchange (ETDEWEB)

    Cilingiroglu, Mehmet, E-mail: mcilingiroglu@yahoo.com; Rollefson, William A.; Mego, David

    2013-07-15

    Congestive heart failure (CHF) secondary to ischemic cardiomyopathy is associated with significant morbidity and mortality despite currently available medical therapy. The Parachute{sup TM} device is a novel left ventricular partitioning device that is delivered percutaneously in the left ventricle (LV) in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction with favorable clinical and LV hemodynamic improvements post-implantation. Here, we do review the current literature and present a case of the Parachute device implantation.

  2. Percutaneous implantation of a parachute device for treatment of ischemic heart failure.

    Science.gov (United States)

    Cilingiroglu, Mehmet; Rollefson, William A; Mego, David

    2013-01-01

    Congestive heart failure (CHF) secondary to ischemic cardiomyopathy is associated with significant morbidity and mortality despite currently available medical therapy. The Parachute(TM) device is a novel left ventricular partitioning device that is delivered percutaneously in the left ventricle (LV) in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction with favorable clinical and LV hemodynamic improvements post-implantation. Here, we do review the current literature and present a case of the Parachute device implantation. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Smart Device for the Determination of Heart Rate Variability in Real Time

    Directory of Open Access Journals (Sweden)

    David Naranjo-Hernández

    2017-01-01

    Full Text Available This work presents a first approach to the design, development, and implementation of a smart device for the real-time measurement and detection of alterations in heart rate variability (HRV. The smart device follows a modular design scheme, which consists of an electrocardiogram (ECG signal acquisition module, a processing module and a wireless communications module. From five-minute ECG signals, the processing module algorithms perform a spectral estimation of the HRV. The experimental results demonstrate the viability of the smart device and the proposed processing algorithms.

  4. Modelling Framework and Assistive Device for Peripheral Intravenous Injections

    Science.gov (United States)

    Kam, Kin F.; Robinson, Martin P.; Gilbert, Mathew A.; Pelah, Adar

    2016-02-01

    Intravenous access for blood sampling or drug administration that requires peripheral venepuncture is perhaps the most common invasive procedure practiced in hospitals, clinics and general practice surgeries.We describe an idealised mathematical framework for modelling the dynamics of the peripheral venepuncture process. Basic assumptions of the model are confirmed through motion analysis of needle trajectories during venepuncture, taken from video recordings of a skilled practitioner injecting into a practice kit. The framework is also applied to the design and construction of a proposed device for accurate needle guidance during venepuncture administration, assessed as consistent and repeatable in application and does not lead to over puncture. The study provides insights into the ubiquitous peripheral venepuncture process and may contribute to applications in training and in the design of new devices, including for use in robotic automation.

  5. Development and evaluation of a new taxonomy of mobility-related assistive technology devices.

    Science.gov (United States)

    Shoemaker, Laura L; Lenker, James A; Fuhrer, Marcus J; Jutai, Jeffrey W; Demers, Louise; DeRuyter, Frank

    2010-10-01

    This article reports on the development of a new taxonomy for mobility-related assistive technology devices. A prototype taxonomy was created based on the extant literature. Five mobility device experts were engaged in a modified Delphi process to evaluate and refine the taxonomy. Multiple iterations of expert feedback and revision yielded consensual agreement on the structure and terminology of a new mobility device taxonomy. The taxonomy uses a hierarchical framework to classify ambulation aids and wheeled mobility devices, including their key features that impact mobility. Five attributes of the new taxonomy differentiate it from previous mobility-related device classifications: (1) hierarchical structure, (2) primary device categories are grouped based on their intended mobility impact, (3) comprehensive inclusion of technical features, (4) a capacity to assimilate reimbursement codes, and (5) availability of a detailed glossary. The taxonomy is intended to support assistive technology outcomes research. The taxonomy will enable researchers to capture mobility-related assistive technology device interventions with precision and provide a common terminology that will allow comparisons among studies. The prominence of technical features within the new taxonomy will hopefully promote research that helps clinicians predict how devices will perform, thus aiding clinical decision making and supporting funding recommendations.

  6. Development of Hand Grip Assistive Device Control System for Old People through Electromyography (EMG Signal Acquisitions

    Directory of Open Access Journals (Sweden)

    Khamis Herman

    2017-01-01

    Full Text Available The hand grip assistive device is a glove to assist old people who suffer from hand weakness in their daily life activities. The device earlier control system only use simple on and off switch. This required old people to use both hand to activate the device. The new control system of the hand grip assistive device was developed to allow single hand operation for old people. New control system take advantages of electromyography (EMG and flex sensor which was implemented to the device. It was programmed into active and semi-active mode operation. EMG sensors were placed on the forearm to capture EMG signal of Flexor Digitorum Profundus muscle to activate the device. Flex sensor was used to indicate the finger position and placed on top of the finger. The signal from both sensors then used to control the device. The new control system allowed single hand operation and designed to prevent user from over depended on the device by activating it through moving their fingers.

  7. Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device

    Science.gov (United States)

    Gohean, Jeffrey R.; George, Mitchell J.; Pate, Thomas D.; Kurusz, Mark; Longoria, Raul G.; Smalling, Richard W.

    2012-01-01

    The purpose of this investigation is to utilize a computational model to compare a synchronized valveless pulsatile left ventricular assist device to continuous flow left ventricular assist devices at the same level of device flow, and to verify the model with in vivo porcine data. A dynamic system model of the human cardiovascular system was developed to simulate support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous, pulsatile, valveless, dual piston positive displacement pump. These results were compared to measurements made during in vivo porcine experiments. Results from the simulation model and from the in vivo counterpart show that the pulsatile pump provides higher cardiac output, left ventricular unloading, cardiac pulsatility, and aortic valve flow as compared to the continuous flow model at the same level of support. The dynamic system model developed for this investigation can effectively simulate human cardiovascular support by a synchronous pulsatile or continuous flow ventricular assist device. PMID:23438771

  8. Everyday use of assistive technology devices in school settings.

    Science.gov (United States)

    Øien, Ingvil; Fallang, Bjørg; Østensjø, Sigrid

    2016-11-01

    To gain more knowledge about ATDs as social-cultural objects in school settings, particularly from the children's perspective. Nine children with cerebral palsy, aged five to six years, were observed 3 days in kindergarten and twice in the first year at primary school. At the primary school, we interviewed the children. During the interviews, the children were shown photos taken during the observations. In addition, dialogues with parents, therapists and school staff were carried out. ATDs seem to have the potential both to exacerbate disability and to enhance selfhood, embodied capacities and participation. Through use, ATDs become social objects with symbolic values that influence their use. Devices corporally embedded into the child's body schema appeared as facilitators for participation in culturally valued activities. In contrast, devices prescribed as medical interventions tended to be greeted with ambivalence by the children themselves, their parents and school staff. A device incorporated into one situation was not necessarily relevant for use in another. In recognizing the value of exploring children's experiences, professionals are left with the challenge of creating space for children to reflect on the worthiness of an ATD across place, time and functionality. Implications for Rehabilitation Used in everyday life, ATDs become social objects with potential both to exacerbate disability and to enhance selfhood, embodied capacities and participation. The child's everyday environment is a vulnerable setting for implementing rehabilitation interventions, such as ATDs. Creating space for children to reflect on the worthiness of an ATD, regarding place, time and functionality, may enhance their participation in everyday life.

  9. Computer-assisted ultrasonic tissue characterization of the heart

    Science.gov (United States)

    Berger, Reinhard; Lieback, Evelin; Hetzer, Roland

    2000-04-01

    In ultrasonic tissue characterization the small reflections originating from the scattering structures inside the tissue are analyzed. To obtain diagnostic performance for tissue characterization by means of analysis of echocardiographic images we use methods of mathematical texture analysis. We investigate whether myocardial changes effect the texture of ultrasonic images and if this could be described using quantitative texture analysis. The texture analysis was computed in a single window of an ultrasound image/sequence covering the inner myocardial septum. Parameters from gray level histogram, co-occurrence matrices, run length statistics and run difference, from power spectrum and fractal dimensions were investigated to provide satisfying and generalizable results for classification of the myocardium. A set of parameters that could discriminate between normal and pathological myocardium were extracted. The results of 142 biopsies were compared with those of texture analysis in echocardiograms of 106 patients suspected having myocarditis. Using the reduced set of parameters the best sensitivity was 89.0% and the specificity was 83.6%. Myocarditis is associated with echocardiographic texture alteration. Texture analysis with methods of digital image processing can reliably identify myocarditis. A suitable solution for a computer-assisted non- invasive support for the diagnosis and detection of myocarditis was found.

  10. A Passively-Suspended Tesla Pump Left Ventricular Assist Device

    Science.gov (United States)

    Izraelev, Valentin; Weiss, William J.; Fritz, Bryan; Newswanger, Raymond K.; Paterson, Eric G.; Snyder, Alan; Medvitz, Richard B.; Cysyk, Joshua; Pae, Walter E.; Hicks, Dennis; Lukic, Branka; Rosenberg, Gerson

    2009-01-01

    The design and initial test results of a new passively suspended Tesla type LAVD blood pump are described. CFD analysis was used in the design of the pump. Overall size of the prototype device is 50 mm in diameter and 75 mm in length. The pump rotor has a density lower than that of blood and when spinning inside the stator in blood it creates a buoyant centering force that suspends the rotor in the radial direction. The axial magnetic force between the rotor and stator restrain the rotor in the axial direction. The pump is capable of pumping up to 10 liters/min at a 70 mmHg head rise at 8000 RPM. The pump has demonstrated a normalized index of hemolysis level below .02 mg/dL for flows between 2 and 9.7 L/min. An inlet pressure sensor has also been incorporated into the inlet cannula wall and will be used for control purposes. One initial in vivo study showed an encouraging result. Further CFD modeling refinements are planned as well as endurance testing of the device. PMID:19770799

  11. Design of a right ventricular mock circulation loop as a test bench for right ventricular assist devices.

    Science.gov (United States)

    Mueller, Indra; Jansen-Park, So-Hyun; Neidlin, Michael; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas; Sonntag, Simon Johannes

    2017-04-01

    Right heart failure (RHF), e.g. due to pulmonary hypertension (PH), is a serious health issue with growing occurrence and high mortality rate. Limited efficacy of medication in advanced stages of the disease constitutes the need for mechanical circulatory support of the right ventricle (RV). An essential contribution to the process of developing right ventricular assist devices (RVADs) is the in vitro test bench, which simulates the hemodynamic behavior of the native circulatory system. To model healthy and diseased arterial-pulmonary hemodynamics in adults (mild and severe PH and RHF), a right heart mock circulation loop (MCL) was developed. Incorporating an anatomically shaped silicone RV and a silicone atrium, it not only enables investigations of hemodynamic values but also suction events or the handling of minimal invasive RVADs in an anatomical test environment. Ventricular pressure-volume loops of all simulated conditions as well as pressure and volume waveforms were recorded and compared to literature data. In an exemplary test, an RVAD was connected to the apex to further test the feasibility of studying such devices with the developed MCL. In conclusion, the hemodynamic behavior of the native system was well reproduced by the developed MCL, which is a useful basis for future RVAD tests.

  12. [Psychological evaluation and support in patients with left ventricular assist devices: preliminary data at 6-month follow-up].

    Science.gov (United States)

    Voltolini, Alessandra; Minotti, Anna; Verde, Alessandro; Cipriani, Manlio; Garascia, Andrea; Turazza, Fabio; Macera, Francesca; Perna, Enrico; Russo, Claudio F; Fumagalli, Emilia; Frigerio, Maria

    2016-11-01

    Heart disease has an impact on patient's identity and self-perception. Taking into account the wide literature about psychological aspects before and after heart transplant, it clearly emerges that there is a lack of data and results for patients up to implantation of ventricular assist devices (VAD). The aim of the present study was to explore quality of life and factors correlated with psychological adjustment in patients supported with VAD. From February 2013 to August 2014, 18 patients (17 male, mean age 57 years) under clinical evaluation before and after VAD implantation were enrolled. During interviews, patients were assessed with EuroQoL-5D questionnaire to monitor improvement of quality of life before implantation and at 3 and 6 months; critical issues, needs and point of views of patients have been described. A significant improvement in the quality of life score was observed at 3 (score 38 [interquartile range 30-40] vs 75 [60-80], ppsychological state investigated by the test showed a clear and positive trend. All patients need to empower through complete information about the device, related risks and life expectancy. Interdisciplinary approach improved compliance with therapy. Successful treatment and efficient psychological care are closely related to assessment and continuous clinical support. This approach ensures a better selection of patients and improves their compliance. Further data are needed to support our preliminary observations and to explore long-term quality of life.

  13. Right ventricular functional analysis utilizing first pass radionuclide angiography for pre-operative ventricular assist device planning: a multi-modality comparison.

    Science.gov (United States)

    Avery, Ryan; Day, Kevin; Jokerst, Clinton; Kazui, Toshinobu; Krupinski, Elizabeth; Khalpey, Zain

    2017-10-10

    Advanced heart failure treated with a left ventricular assist device is associated with a higher risk of right heart failure. Many advanced heart failures patients are treated with an ICD, a relative contraindication to MRI, prior to assist device placement. Given this limitation, left and right ventricular function for patients with an ICD is calculated using radionuclide angiography utilizing planar multigated acquisition (MUGA) and first pass radionuclide angiography (FPRNA), respectively. Given the availability of MRI protocols that can accommodate patients with ICDs, we have correlated the findings of ventricular functional analysis using radionuclide angiography to cardiac MRI, the reference standard for ventricle function calculation, to directly correlate calculated ejection fractions between these modalities, and to also assess agreement between available echocardiographic and hemodynamic parameters of right ventricular function. A retrospective review from January 2012 through May 2014 was performed to identify advanced heart failure patients who underwent both cardiac MRI and radionuclide angiography for ventricular functional analysis. Nine heart failure patients (8 men, 1 woman; mean age of 57.0 years) were identified. The average time between the cardiac MRI and radionuclide angiography exams was 38.9 days (range: 1 - 119 days). All patients undergoing cardiac MRI were scanned using an institutionally approved protocol for ICD with no device-related complications identified. A retrospective chart review of each patient for cardiomyopathy diagnosis, clinical follow-up, and echocardiogram and right heart catheterization performed during evaluation was also performed. The 9 patients demonstrated a mean left ventricular ejection fraction (LVEF) using cardiac MRI of 20.7% (12 - 40%). Mean LVEF using MUGA was 22.6% (12 - 49%). The mean right ventricular ejection fraction (RVEF) utilizing cardiac MRI was 28.3% (16 - 43%), and the mean RVEF calculated by

  14. Sensor-Based Assistive Devices for Visually-Impaired People: Current Status, Challenges, and Future Directions

    Directory of Open Access Journals (Sweden)

    Wafa Elmannai

    2017-03-01

    Full Text Available The World Health Organization (WHO reported that there are 285 million visuallyimpaired people worldwide. Among these individuals, there are 39 million who are totally blind. There have been several systems designed to support visually-impaired people and to improve the quality of their lives. Unfortunately, most of these systems are limited in their capabilities. In this paper, we present a comparative survey of the wearable and portable assistive devices for visuallyimpaired people in order to show the progress in assistive technology for this group of people. Thus, the contribution of this literature survey is to discuss in detail the most significant devices that are presented in the literature to assist this population and highlight the improvements, advantages, disadvantages, and accuracy. Our aim is to address and present most of the issues of these systems to pave the way for other researchers to design devices that ensure safety and independent mobility to visually-impaired people.

  15. Electrical storm in the early phase of HeartMate® II device implantation: Incidence, risk factors and prognosis.

    Science.gov (United States)

    Corre, Jerome; Picard, François; Garcia, Rodrigue; Zemmoura, Adlane; Derval, Nicolas; Denis, Arnaud; Romen, Antoine; Nubret, Karine; Jais, Pierre; Haissaguerre, Michel; Dos Santos, Pierre; Barandon, Laurent; Sacher, Frederic

    2017-12-04

    Ventricular arrhythmia is common after left ventricular assist device (LVAD) implantation, especially in the early postoperative phase (<30 days). To identify the incidence of and risk factors for electrical storm (ES) occurring within 30 days of HeartMate® II implantation. We reviewed data from all consecutive patients undergoing HeartMate® II device implantation at our institution from January 2008 to December 2014. Patient demographic data, pharmacotherapies and outcomes were collected. The primary endpoint was occurrence of early ES (within 30 days of surgery), defined as three or more separate episodes of sustained ventricular arrhythmia within a 24-hour interval, requiring appropriate therapy. Forty-three patients (mean age 56.7±11.2 years; 39 men) were included. At HeartMate® II implantation, mean left ventricular ejection fraction was 20±5%, 32 (74.4%) patients had ischaemic cardiomyopathy and 31 (72.1%) were implanted with an indication of bridge to cardiac transplantation. During follow-up, 12 (27.9%) patients experienced early ES after HeartMate® II implantation (median delay 9.1±7.8 days). Early ES was more frequent in larger patients (body surface area 1.99 vs 1.81 m2; P<0.01), tended to be associated with previous sustained ventricular tachycardia (50.0% vs 22.6%; P=0.08), previous implantable cardioverter-defibrillator implantation (66.7% vs 38.7%; P=0.09), discontinuation of long-term beta-blocker therapy (75.0% vs 45.2%; P=0.08), weaning of adrenergic drugs after the third day (66.7% vs 35.5%; P=0.06) and the use of extracorporeal life support (50% vs 22.6%; P=0.079), but was not associated with the cardiomyopathy aetiology or the indication for assistance. Catheter ventricular tachycardia ablation was performed in six (14.0%) patients. Early ES was associated with a significantly higher all-cause mortality rate at the 30th day (33.3% vs 6.5%; P=0.02). ES is a common and pejorative feature in the early postoperative period. Copyright

  16. In vivo assessment of hemocompatibility of a ventricular assist device in healthy swine.

    Science.gov (United States)

    Sacristán, Catarina; Escobedo, Carlos R; Bojalil, Rafael; Izaguirre, Raúl A; Cortina, Evelyn; Aranda, Alberto; Catrip, Jorge; Lesprón, Ma Del Carmen; Springall, Rashidi; Sacristán, Emilio

    2010-01-01

    To assess the hemocompatible performance of a novel implantable pneumatic ventricular assist device (VAD, Innovamédica, México) in healthy swine. The aim of this pilot study was first, to determine if short-term VAD implantation elicited remarkable inflammatory response above that expected from surgical trauma; and second, to assess if heparinized or passivated VAD coatings, in combination with systemic anticoagulant or antiaggregant therapies, modified the VAD's hemocompatible performance. Hemodynamic, physicologic, inflammatory and histological parameters were measured in 27 pigs receiving VAD support for six hours, testing combinations of heparinized or passivated VAD coatings and systemic anticoagulant/ antiaggregant therapies. Mean concentrations of interleukin -1 B (IL-1B), interleukin -6 (IL-6), C-reactive protein (CRP), or thrombin-antithrombin III (TAT) complexes (coagulation indicator) were measured from blood. ANOVA statistics were employed. No substantial increases in mean IL -1B, IL-6, CRP, or TAT were obtained during VAD support. Hemodynamic ans physiologic parameters were normal. We found no evidence of thromboembolisms or micro-infarctions in heart and lung samples. No major coaguli/deposits were found in VAD compartments. Overall, no remarkable differences in measurements were found using heparinized, passivated, or uncoated VAD, or with systemic anticoagulation, antiaggregant therapy, or no treatment. Our findings demonstrate, firstly, that during the time-period tested, the VAD elicited negligible inflammation above the effects of surgical trauma; and secondly, that little coagulation was observed upon VAD support in any of the cases tested. Contemplating further validation studies, our data indicate that the Innovamédica VAD is a highly hemocompatible system.

  17. Long-term durability test of axial-flow ventricular assist device under pulsatile flow.

    Science.gov (United States)

    Nishida, Masahiro; Kosaka, Ryo; Maruyama, Osamu; Yamane, Takashi; Shirasu, Akio; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2017-03-01

    A long-term durability test was conducted on a newly developed axial-flow ventricular assist device (VAD) with hydrodynamic bearings. The mock circulatory loop consisted of a diaphragm pump with a mechanical heart valve, a reservoir, a compliance tank, a resistance valve, and flow paths made of polymer or titanium. The VAD was installed behind the diaphragm pump. The blood analog fluid was a saline solution with added glycerin at a temperature of 37 °C. A pulsatile flow was introduced into the VAD over a range of flow rates to realize a positive flow rate and a positive pressure head at a given impeller rotational speed, yielding a flow rate of 5 L/min and a pressure of 100 mmHg. Pulsatile flow conditions were achieved with the diastolic and systolic flow rates of ~0 and 9.5 L/min, respectively, and an average flow rate of ~5 L/min at a pulse rate of 72 bpm. The VAD operation was judged by not only the rotational speed of the impeller, but also the diastolic, systolic, and average flow rates and the average pressure head of the VAD. The conditions of the mock circulatory loop, including the pulse rate of the diaphragm pump, the fluid temperature, and the fluid viscosity were maintained. Eight VADs were tested with testing periods of 2 years, during which they were continuously in operation. The VAD performance factors, including the power consumption and the vibration characteristics, were kept almost constant. The long-term durability of the developed VAD was successfully demonstrated.

  18. Geometry and fusion of aortic valves from pulsatile flow ventricular assist device patients.

    Science.gov (United States)

    May-Newman, Karen; Mendoza, Annamarie; Abulon, Dina J K; Joshi, Mrunalini; Kunda, Anand; Dembitsky, Walter

    2011-03-01

    Aortic valve commissural fusion is a process in which fibrous tissue is deposited at the aortic valve commissures, creating adhesion between leaflets and preventing opening. Fusion has recently been associated with the implantation of left ventricular assist devices (VADs), affecting upwards of 50% of patients in recent studies. Aortic incompetence has also been associated with pulsatile VAD use, but a specific structural mechanism has not been identified. The study aim was to measure aortic valve geometry and fusion in tissue samples from explanted hearts of VAD recipients and to identify features that might explain the development of aortic valve dysfunction. The diameter, perimeter and thickness of the aortic root, as well as the height, edge length and thickness of each of the three aortic leaflets were measured in seven valves. Histological studies were performed of both fused and unfused leaflets. The aortic root geometry showed an elliptical aorta, with asymmetric leaflets. The right coronary leaflet had the greatest edge length, but was thinnest. The other two leaflets were smaller, but slightly thicker. Overall, the aorta and valve geometry was within the normal range. Fusion was found in five of the seven valves studied, and often observed in multiple leaflets. Fusion length correlated loosely with the time of VAD support. Tissue from both fused and unfused valves showed unilateral fibrosis in the leaflets, and a loss of the laminar tissue structure that was related to the duration of VAD support. These findings support previous observations that pathological changes occur in the aortic valves of VAD patients shortly after implantation. While the tissue exhibits abnormalities in the structure, the geometry does not show gross remodeling such as annular dilatation or leaflet lengthening that might precede the development of aortic valve dysfunction. These changes are associated with the development of aortic valve fusion, and may be related to the

  19. Costs and reimbursement gaps after implementation of third-generation left ventricular assist devices.

    Science.gov (United States)

    Mishra, Vinod; Geiran, Odd; Fiane, Arnt E; Sørensen, Gro; Andresen, Sølvi; Olsen, Ellen K; Khushi, Ishtiaq; Hagen, Terje P

    2010-01-01

    The purpose of this study was to compare and contrast total hospital costs and subsequent reimbursement of implementing a new program using a third-generation left ventricular assist device (LVAD) in Norway. Between July 2005 and March 2008, the total costs of treatment for 9 patients were examined. Costs were calculated for three periods-the pre-implantation LVAD phase, the LVAD implantation phase and the post-implantation LVAD phase-as well as for total hospital care. Patient-specific costs were obtained prospectively from patient records and included personnel resources, medication, blood products, blood chemistry and microbiology, imaging, and procedure costs including operating room costs. Overhead costs were registered retrospectively and allocated to the specific patient by pre-defined allocation keys. Finally, patient-specific costs and overhead costs were aggregated into total patient costs. The average total patient cost in 2007 U.S. dollars was $735,342 and the median was $613,087 (range $342,581 to $1,256,026). The mean length of stay was 77 days (range 40 to 127 days). For the LVAD implantation phase, the mean cost was $457,795 and median cost was $458,611 (range $246,239 to $677,680). The mean length of stay for the LVAD implantation phase was 55 days (range 25 to 125 days). The diagnosis-related group (DRG) reimbursement (2007) was $143,192. There is significant discrepancy between actual hospital costs and the current Norwegian DRG reimbursement for the LVAD procedure. This discrepancy can be partly explained by excessive costs related to the introduction of a new program with new technology. Costly innovations should be considered in price setting of reimbursement for novel technology. Copyright (c) 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  20. Interaction between physical activity and continuous-flow left ventricular assist device function in outpatients.

    Science.gov (United States)

    Hu, Sharon X H; Keogh, Anne M; Macdonald, Peter S; Kotlyar, Eugene; Robson, Desiree; Harkess, Michelle; Granger, Emily; Dhital, Kumud; Jansz, Paul; Spratt, Phillip; Hayward, Christopher S

    2013-03-01

    Studies have shown that pump output by continuous-flow left ventricular assist devices (LVADs) increases with graded exercise testing. However, data on pump behavior during activities of daily living and sleep, where cardiac output requirements vary markedly, are lacking. We sought to determine pump parameters and activity levels in stable patients receiving outpatient LVAD therapy. Eleven outpatients (mean age 51 ± 14 years, 9 male) with centrifugal continuous-flow LVADs underwent monitoring of LVAD flow, heart rate (HR), energy expenditure, and physical activity over 1 week in an outpatient setting. Physical activity was recorded with the use of a combined pedometer, accelerometer, and calorimeter Sensewear armband. Pump, HR, and physical activity parameters were time matched for correlation analysis. Outpatients had an average pump flow of 5.67 ± 1.27 L/min and engaged predominately in low levels of physical activity (mean daily step count 3,249/day). Across the entire cohort, pump flow exhibited strong univariate relationships with patients' energy expenditure (r = 0.73), step count (r = 0.69), HR (r = 0.73), sleep (r = -0.89), and skin temperature (r = -0.85; P < .0001 for all). Multivariate analysis suggested that pump output was predominantly affected by recumbent position, energy expenditure and skin temperature (r(2) = 0.84; P < .0001). Pump flow and power consumption were significantly lower during sleep than during wake periods (5.48 ± 1.31 L/min vs 5.80 ± 1.26 L/min; P < .001). Pump output from continuous-flow LVADs is adaptive to changes in activities of daily living. Circadian variation in pump flow is mostly explained by recumbency and activity levels. Despite adequate pump flow, many LVAD patients continue to live sedentary lifestyles. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  1. Patients with continuous-flow left ventricular assist devices provide insight in human baroreflex physiology.

    Science.gov (United States)

    Tank, Jens; Heusser, Karsten; Malehsa, Doris; Hegemann, Katrin; Haufe, Sven; Brinkmann, Julia; Tegtbur, Uwe; Diedrich, André; Bara, Christoph; Jordan, Jens; Strüber, Martin

    2012-09-01

    The superior clinical outcome of new continuous-flow left ventricular assist devices (LVADs) challenges the physiological dogma that cardiovascular autonomic homeostasis requires pulsatile blood flow and pressure. We tested the hypothesis that continuous-flow LVADs impair baroreflex control of sympathetic nerve traffic, thus further exacerbating sympathetic excitation. We included 9 male heart failure patients (26-61 years; 18.9-28.3 kg/m(2)) implanted with a continuous-flow LVAD. We recorded ECG, respiration, finger blood pressure, brachial blood pressure, and muscle sympathetic nerve activity. After baseline measurements had been taken, patients underwent autonomic function testing including deep breathing, a Valsalva maneuver, and 15° head-up tilt. Finally, we increased the LVAD speed in 7 patients. Spontaneous sympathetic baroreflex sensitivity was analyzed. Brachial blood pressure was 99±4 mm Hg with 14±2 mm Hg finger pulse pressure. Muscle sympathetic nerve activity bursts showed a normal morphology, were linked to the cardiac cycle, and were suppressed during blood pressure increases. Mean burst frequency was lower compared with age- and body mass index-matched controls in 2 patients, slightly increased in 4 patients, and increased in 2 patients (P=0.11). Muscle sympathetic nerve activity burst latency and the median values of the burst amplitude distribution were similar between groups. Muscle sympathetic nerve activity increased 4±1 bursts per minute with head-up tilt (P<0.0003) and decreased 3±4 bursts per minute (P<0.031) when LVAD speed was raised. The mean sympathetic baroreflex slope was -3.75±0.79%/mm Hg in patients and -3.80±0.55%/mm Hg in controls. We conclude that low pulse pressure levels are sufficient to restrain sympathetic nervous system activity through baroreflex mechanisms.

  2. False-positive hepatitis C virus serology after placement of a ventricular assistance device.

    Science.gov (United States)

    Durand, C M; Marr, K A; Ostrander, D; Subramanian, A; Valsamakis, A; Cox, A; Neofytos, D

    2016-02-01

    Ventricular assist devices (VADs) have been associated with immune activation and sensitization. We observed several cases of false-positive (FP) hepatitis C virus (HCV) antibody (Ab) tests in patients being evaluated for orthotopic heart transplant (OHT), prompting us to investigate this further. We reviewed all VAD and OHT cases at Johns Hopkins from 2005 to 2012. FP HCV serology was defined as an equivocal or low-positive HCV Ab, plus either (i) a negative recombinant immunoblot (RIBA) and/or HCV nucleic acid test (NAT), or (ii) an indeterminate RIBA and negative NAT. In 53 patients with available HCV testing, nearly 40% of patients (21/53: 39.6%) developed FP HCV Ab tests after VAD placement: 4 patients had negative NAT, 12 had negative RIBA, and 5 had an indeterminate RIBA and negative NAT. All patients with indeterminate RIBA tests had isolated reactivity to the same HCV protein, c100p/5-1-1p (NS4b protein). In 3 of 4 VAD patients who had OHT and repeat HCV Ab testing after VAD removal, repeat HCV Ab was negative (699-947 days after OHT); in 1 case, FP HCV serology persisted (5 days after OHT). Thirteen patients had OHT alone and none developed a FP HCV Ab. FP HCV Ab results following VAD placement are very common. Reversal of FP serology in several patients after VAD removal is suggestive of a possible association with the VAD hardware. Clinicians should be aware of this phenomenon, as it could lead to delays in determining eligibility for OHT and increased costs. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. The use of eptifibatide for suspected pump thrombus or thrombosis in patients with left ventricular assist devices.

    Science.gov (United States)

    Tellor, Bethany R; Smith, Jennifer R; Prasad, Sunil M; Joseph, Susan M; Silvestry, Scott C

    2014-01-01

    Pump thrombosis in patients with left ventricular assist devices (LVADs) continues to present treatment challenges. Anti-coagulation strategies used to treat this complication are empiric and without firm data for guidance. The addition of a platelet glycoprotein IIb/IIIa inhibitor to intravenous anti-coagulation has been suggested by several case series and recent guidelines. The aim of this study was to evaluate our use of eptifibatide for the treatment of suspected pump thrombus/thrombosis. This retrospective, single-center cohort study was performed at Barnes-Jewish Hospital. The medical informatics system was queried to identify all LVAD patients who received eptifibatide for suspected pump thrombus/thrombosis from January 1, 2011, through April 30, 2013. A total of 17 patients (16 HeartMate II [Thoratec, Pleasanton, CA], 1 HeartWare [HeartWare International Inc, Framingham, MA]) with 22 separate administration attempts received eptifibatide (dose range, 0.1-2 μg/kg/min) for suspected pump thrombus/thrombosis presenting as one or more of the following findings: elevated lactate dehydrogenase, decreased haptoglobin, elevated plasma free hemoglobin, LVAD dysfunction, or new, persistently high LVAD power. The mean time from device implantation to eptifibatide therapy was 47.34 days (range, 3.88-397.67 days). Of the 22 attempts, 5 (22.7%) resulted in resolution of 1 or more patient-specific indicators of LVAD thrombus/thrombosis. Three patients (17.6%) had resolution of an indicator while also remaining free from continued hemolysis, death, pump exchange, or emergent heart transplant. Bleeding events were common, with 11 patients (64.7%) experiencing bleeding during the infusion. Seven patients (41.2%) died, with intraparenchymal hemorrhage as the cause of death in 2 patients. Pump exchange was performed in 3 patients. Our limited experience indicates the risk of using eptifibatide outweighs the proposed benefit of salvaging the existing LVAD in the setting of

  4. Effectiveness of device-assisted ultrasound-guided steroid injection for treating plantar fasciitis.

    Science.gov (United States)

    Chen, Chien-Min; Chen, Jenq-Shyong; Tsai, Wen-Chung; Hsu, Hung-Chih; Chen, Kai-Hua; Lin, Chu-Hsu

    2013-07-01

    The aim of this study was to investigate the effectiveness of device-assisted ultrasound-guided steroid injection for treating plantar fasciitis. An ultrasound-guided injection device designed with space for securing a transducer and syringe was used to guide steroid injection. Patients with unilateral plantar fasciitis were enrolled and randomly divided into device-assisted ultrasound-guided and palpation-guided groups. Pain intensity was measured using a visual analog scale and tenderness threshold. Ultrasound and pain intensity evaluations were performed before injection and at 3 wks and at 3 mos postinjection. Betamethasone (7 mg) and 1% lidocaine (0.5 ml) were injected into the inflamed plantar fascia. Thirty-three patients who received either device-assisted ultrasound-guided or palpation-guided injection had significantly lower visual analog scale scores (P plantar fascia (3/16 vs. 9/16; P = 0.033) than the palpation-guided group did at 3 mos postinjection. The heel pad was significantly thin (P = 0.004) in the palpation-guided group postinjection. Device-assisted ultrasound-guided injection for treating plantar fasciitis results in better therapeutic outcomes than palpation-guided injection does.

  5. The embodiment of assistive devices-from wheelchair to exoskeleton

    Science.gov (United States)

    Pazzaglia, Mariella; Molinari, Marco

    2016-03-01

    Spinal cord injuries (SCIs) place a heavy burden on the healthcare system and have a high personal impact and marked socio-economic consequences. Clinically, no absolute cure for these conditions exists. However, in recent years, there has been an increased focus on new robotic technologies that can change the frame we think about the prognosis for recovery and for treating some functions of the body affected after SCIs. This review has two goals. The first is to assess the possibility of the embodiment of functional assistive tools after traumatic disruption of the neural pathways between the brain and the body. To this end, we will examine how altered sensorimotor information modulates the sense of the body in SCI. The second goal is to map the phenomenological experience of using external tools that typically extend the potential of the body physically impaired by SCI. More specifically, we will focus on the difference between the perception of one's physically augmented and non-augmented affected body based on observable and measurable behaviors. We discuss potential clinical benefits of enhanced embodiment of the external objects by way of multisensory interventions. This review argues that the future evolution of human robotic technologies will require adopting an embodied approach, taking advantage of brain plasticity to allow bionic limbs to be mapped within the neural circuits of physically impaired individuals.

  6. [Fondaparinux as an alternative anticoagulant in heparin-induced thrombocytopenia in the patient with a ventricular assist device].

    Science.gov (United States)

    Cegarra-Sanmartín, V; Paniagua, P; Galán, J; Muñoz, C; Moral, M V

    2013-11-01

    Heparin-induced thrombocytopenia is a reaction associated with the use of this drug. It occurs in up to 3% of patients treated for at least 5 days. Its treatment is to stop the heparin, and according to patient needs, replace it with another anticoagulant. We present a patient who, after a heart transplant, and the need for a ventricular assist device, required anticoagulation. The patient developed heparin-induced thrombocytopenia. Heparin was stopped and anticoagulation was replaced by fondaparinux. The peri-operative complications and the management of the coagulation are described. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  7. Design Rationale and Preclinical Evaluation of the HeartMate 3 Left Ventricular Assist System for Hemocompatibility.

    Science.gov (United States)

    Bourque, Kevin; Cotter, Christopher; Dague, Charles; Harjes, Daniel; Dur, Onur; Duhamel, Julien; Spink, Kaitlyn; Walsh, Kelly; Burke, Edward

    2016-01-01

    The HeartMate 3 (HM3) left ventricular assist device (LVAD) is designed to support advanced heart failure patients. This centrifugal flow pump has a magnetically levitated rotor, artificial pulse, textured blood-contacting surfaces, optimized fluid dynamics, large blood-flow gaps, and low shear stress. Preclinical tests were conducted to assess hemocompatibility. A computational fluid dynamics (CFD) model guided design for low shear stress and sufficient washing. Hemolysis testing was conducted on six pumps. Plasma-free hemoglobin (PfHb) and modified index of hemolysis (MIH) were compared with HeartMate II (HMII). CFD showed secondary flow path residence times between 27 and 798 min, comparable with main flow residence times between 118 and 587 min; HM3 vs. HMII shear stress exposure above 150 Pa was 3.3 vs. 11 mm within the pump volume and 134 vs. 604 mm on surfaces. In in vitro hemolysis tests at 2, 5, and 10 L/min, average pfHb 6 hours after test initiation was 58, 74, and 157 mg/dl, compared with 112, 123, and 353 mg/dl for HMII. The HM3/HMII ratio of average MIH at 2, 5, and 10 L/min was 0.29, 0.36, and 0.22. Eight 60 day bovine implants were tested with average flow rates from 5.6 to 6.4 L/min with no device failures, thrombosis, or hemolysis. Results support advancing HM3 to clinical trials.

  8. The physiological effect of a 'climb assist' device on vertical ladder climbing.

    Science.gov (United States)

    Barron, Peter James; Burgess, Katherine; Cooper, Kay; Stewart, Arthur D

    2017-07-01

    'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O2 and rate of perceived exertion (RPE). All three variables decreased significantly (p climb assist with [Formula: see text]O2 decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O2 decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O2, HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O2, HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

  9. Minimally Invasive Procedures - Direct and Video-Assisted Forms in the Treatment of Heart Diseases

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Josué Viana Neto, E-mail: jvcn@uol.com.br [Instituto do Coração do Nordeste (INCONE), Fortaleza, CE (Brazil); Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil); Melo, Emanuel Carvalho; Silva, Juliana Fernandes [Instituto do Coração do Nordeste (INCONE), Fortaleza, CE (Brazil); Rebouças, Leonardo Lemos; Corrêa, Larissa Chagas; Germano, Amanda de Queiroz [Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil); Machado, João José Aquino [Instituto do Coração do Nordeste (INCONE), Fortaleza, CE (Brazil)

    2014-03-15

    Minimally invasive cardiovascular procedures have been progressively used in heart surgery. To describe the techniques and immediate results of minimally invasive procedures in 5 years. Prospective and descriptive study in which 102 patients were submitted to minimally invasive procedures in direct and video-assisted forms. Clinical and surgical variables were evaluated as well as the in hospital follow-up of the patients. Fourteen patients were operated through the direct form and 88 through the video-assisted form. Between minimally invasive procedures in direct form, 13 had aortic valve disease. Between minimally invasive procedures in video-assisted forms, 43 had mitral valve disease, 41 atrial septal defect and four tumors. In relation to mitral valve disease, we replaced 26 and reconstructed 17 valves. Aortic clamp, extracorporeal and procedure times were, respectively, 91,6 ± 21,8, 112,7 ± 27,9 e 247,1 ± 20,3 minutes in minimally invasive procedures in direct form. Between minimally invasive procedures in video-assisted forms, 71,6 ± 29, 99,7 ± 32,6 e 226,1 ± 42,7 minutes. Considering intensive care and hospitalization times, these were 41,1 ± 14,7 hours and 4,6 ± 2 days in minimally invasive procedures in direct and 36,8 ± 16,3 hours and 4,3 ± 1,9 days in minimally invasive procedures in video-assisted forms procedures. Minimally invasive procedures were used in two forms - direct and video-assisted - with safety in the surgical treatment of video-assisted, atrial septal defect and tumors of the heart. These procedures seem to result in longer surgical variables. However, hospital recuperation was faster, independent of the access or pathology.

  10. The total artificial heart for biventricular heart failure and beyond.

    Science.gov (United States)

    Kasirajan, Vigneshwar; Tang, Daniel G; Katlaps, Gundars J; Shah, Keyur B

    2012-05-01

    Treatment options for late-stage biventricular heart failure are limited but include medical therapy with intravenous inotropes, biventricular assist devices (Bi-VADs) and the total artificial heart (TAH). In this manuscript, we review the indications, surgical techniques and outcomes for the TAH. The TAH offers biventricular replacement, rather than 'assistance', as the device is placed orthotopically after excision of the entire ventricular myocardium and all four native valves. In contrast to patients with Bi-VADs, patients with the TAH have no postoperative inotrope requirements, arrhythmias or inflow/outflow cannulae-related complications. Additionally, patients participate in rehabilitation early after device placement and the development of a portable drive may facilitate hospital discharge in the USA. Furthermore, total heart replacement may be ideal for heart failure associated with unique anatomical and mechanical complications. The TAH is an effective therapeutic option for the treatment of patients dying of heart failure who may not be suitable candidates for left ventricular assist devices.

  11. Electrocardiograms and heart rate signals a short distance transfer to the Android type of mobile devices, saving energy and bandwidth expenditure

    Directory of Open Access Journals (Sweden)

    Dalius Miežinis

    2013-09-01

    Full Text Available Electrocardiograms and heart rate signals short distance transfer to mobile Android devices problem is examined. Energy saving and efficient use of bandwidth issues for signals transfer is discussed. Electrocardiograms and heart rate signaling proximity to mobile Android devices implementation possibilities is analyzed. Electrocardiograms and heart rate signals short distance transfer to mobile Android devices is proposed.

  12. Towards Optimization of a Novel Trileaflet Polymeric Prosthetic Heart Valve Via Device Thrombogenicity Emulation (DTE)

    Science.gov (United States)

    Claiborne, Thomas E.; Xenos, Michalis; Sheriff, Jawaad; Chiu, Wei-Che; Soares, Joao; Alemu, Yared; Gupta, Shikha; Judex, Stefan; Slepian, Marvin J.; Bluestein, Danny

    2013-01-01

    Aortic stenosis the is most prevalent and life threatening form of valvular heart disease. It is primarily treated via open-heart surgical valve replacement with either a tissue or mechanical prosthetic heart valve (PHV), each prone to degradation and thrombosis, respectively. Polymeric PHVs may be optimized to eliminate these complications, and they may be more suitable for the new transcatheter aortic valve replacement (TAVR) procedure and in devices like the Total Artificial Heart. However, the development of polymer PHVs has been hampered by persistent in vivo calcification, degradation, and thrombosis. To address these issues, we have developed a novel surgically implantable polymer PHV comprised of a new thermoset polyolefin called xSIBS, in which key parameters were optimized for superior functionality via our Device Thrombogenicity Emulation (DTE) methodology. In this parametric study, we compared our homogeneous optimized polymer PHV to a prior composite polymer PHV and to a benchmark tissue valve. Our results show significantly improved hemodynamics and reduced thrombogenicity in the optimized polymer PHV compared to the other valves. These results indicate that our new design may not require anticoagulants and may be more durable than its predecessor, and validates the improvement, towards optimization, of this novel polymeric PHV design. PMID:23644615

  13. [Analysis of using assistive devices by patients suffering from cerebral palsy - preliminary report].

    Science.gov (United States)

    Zeńczak-Praga, Krystyna; Zgorzalewicz-Stachowiak, Małgorzata; Cesar, Kinga

    2015-11-01

    Cerebral palsy (CP) is still significant health and social issue in the world. Adults who suffer from that illness have problem with mobility which make their functioning much harder. Common symptoms include spasticity, chronic pain of musculoskeletal system, disturbance of sensation, epilepsy or mental retardation. The aim of the study was analysis of assistive devices used by patients with CP through childhood and adulthood. The results were compared with the situation in this field of CP patients in other countries. The study involved 30 patients with CP in age between 20-43 living in Poznan and under the care of Occupational Therapy Workshop and Enviromental Self-help Houses. The research method was questionnaire which was directed to caregivers of adults with CP. They were asked about diagnosis, accompanying symptoms as well as assistive devices used during childhood and adulthood. During childhood wheelchair and standing frame were used the most often while during adulthood the most common were also the first mentioned above as well as rehabilitation lift. Although unfavourable evaluation of fitting assistive devices, majority of caregivers of CP sufferer claimed that there was varying improvement in patients motor functionality. Comprehensive rehabilitation and assistive devices are necessary for patients with CP during adulthood not less than during childhood. Wheelchairs are even more essential for adults than for children. © 2015 MEDPRESS.

  14. A Systematic Review on Existing Measures for the Subjective Assessment of Rehabilitation and Assistive Robot Devices

    Directory of Open Access Journals (Sweden)

    Yiannis Koumpouros

    2016-01-01

    Full Text Available The objective of the current study is to identify and classify outcome measures currently used for the assessment of rehabilitation or assistive robot devices. We conducted a systematic review of the literature using PubMed, MEDLINE, CIRRIE, and Scopus databases for studies that assessed rehabilitation or assistive robot devices from 1980 through January 2016. In all, 31 articles met all inclusion criteria. Tailor-made questionnaires were the most commonly used tool at 66.7%, while the great majority (93.9% of the studies used nonvalidated instruments. The study reveals the absence of a standard scale which makes it difficult to compare the results from different researchers. There is a great need, therefore, for a valid and reliable instrument to be available for use by the intended end users for the subjective assessment of robot devices. The study concludes by identifying two scales that have been validated in general assistive technology devices and could support the scope of subjective assessment in rehabilitation or assistive robots (however, with limited coverage and a new one called PYTHEIA, recently published. The latter intends to close the gap and help researchers and developers to evaluate, assess, and produce products that satisfy the real needs of the end users.

  15. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro

    Directory of Open Access Journals (Sweden)

    Jia Ke

    2016-01-01

    Conclusions: This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures. Further, more in vitro experiments are needed to improve the system operation and its safety.

  16. Hemodynamic stress echocardiography in patients supported with a continuous-flow left ventricular assist device

    DEFF Research Database (Denmark)

    Andersen, Mads; Gustafsson, Finn; Madsen, Per Lav

    2010-01-01

    Functional assessment of continuous-flow left ventricular assist devices (LVADs) is usually performed with the patient at rest. This study compared echocardiographic indices of contraction and filling pressure with invasive measures in 12 ambulatory LVAD patients undergoing symptom-limited bicycl...

  17. Numerical simulation of the influence of a left ventricular assist device on the cardiovascular system

    NARCIS (Netherlands)

    Verkerke, GJ; Geertsema, AA; Mihaylov, D; Blanksma, PK; Rakhorst, G

    2000-01-01

    The PUCA (pulsatile catheter) pump is a left ventricular assist device (LVAD) capable of unloading the left ventricle (LV) and improving coronary flow by providing a counterpulsation effect. If consists of an extracorporeal located membrane pump, coupled to a transarterial catheter that enters the

  18. Noninvasive arterial blood pressure waveforms in patients with continuous-flow left ventricular assist devices

    NARCIS (Netherlands)

    Martina, Jerson R.; Westerhof, Berend E.; de Jonge, Nicolaas; van Goudoever, Jeroen; Westers, Paul; Chamuleau, Steven; van Dijk, Diederik; Rodermans, Ben F. M.; de Mol, Bas A. J. M.; Lahpor, Jaap R.

    2014-01-01

    Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow left ventricular assist devices (cf-LVADs). We investigated the accuracy and characteristics of noninvasive blood pressure during cf-LVAD support.

  19. Dutch technical specification (NTA 8070) on devices for assisted reproductive technologies.

    NARCIS (Netherlands)

    Wetzels, A.M.M.; Kastrop, P.M.

    2010-01-01

    In 2006 the Dutch Society for Clinical Embryologists (KLEM) approached the Netherlands Standardisation Institute (NEN) for advice regarding the lack of safety and quality specifications for medical devices used in assisted reproductive technology. A project plan was drafted in accordance with

  20. Electric field and interface charge extraction in field-plate assisted RESURF devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Heringa, Anco; Ferrara, A.; Steeneken, Peter G.; Schmitz, Jurriaan; Hueting, Raymond Josephus Engelbart

    2015-01-01

    A methodology for extracting the lateral electric field (Ex) in the drain extension of thin silicon-on-insulator high-voltage field-plate assisted reduced surface field (RESURF) devices is detailed including its limits and its accuracy. Analytical calculations and technology computer-aided design

  1. Extraction of the Electric Field in Field Plate Assisted RESURF Devices

    NARCIS (Netherlands)

    Boksteen, B.K.; Dhar, S.; Heringa, A.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

    2012-01-01

    It has previously been reported that the lateral electric field (Ex) in the drain extension of thin SOI HV (700V) field plate assisted RESURF devices can be extracted from their ID-VD characteristics in the subthreshold regime. In this work the prerequisites for valid field extraction and the

  2. Intelligent speed adaptation as an assistive device for drivers with acquired brain injury

    DEFF Research Database (Denmark)

    Klarborg, Brith; Lahrmann, Harry Spaabæk; Agerholm, Niels

    2012-01-01

    Intelligent speed adaptation (ISA) was tested as an assistive device for drivers with an acquired brain injury (ABI). The study was part of the “Pay as You Speed” project (PAYS) and used the same equipment and technology as the main study (Lahrmann et al., in press-a, in press-b). Two drivers...

  3. A survey of the use of hearing aid and assistive devices among the ...

    African Journals Online (AJOL)

    The study concluded that the effectiveness of hearing aids and other assistive devices for the pupils in the school system however depend on adequate monitoring techniques as well as adequate diagnosis by the audiologists. African Journal of Cross-Cultural Psychology and Sport Facilitation Vol. 6 2004: 96-105 ...

  4. Numerical simulation of the pulsating catheter pump : A left ventricular assist device

    NARCIS (Netherlands)

    Verkerke, GJ; Mihaylov, D; Geertsema, AA; Lubbers, J; Rakhorst, G

    1999-01-01

    The pulsating catheter (PUCA) pump, a left ventricular assist device, consists of a hydraulically or pneumatically driven membrane pump, extracorporeally placed and mounted to a valved catheter. The catheter is introduced into an easily accessible artery and positioned with its distal tip in the

  5. A Systematic Review on Existing Measures for the Subjective Assessment of Rehabilitation and Assistive Robot Devices.

    Science.gov (United States)

    Koumpouros, Yiannis

    2016-01-01

    The objective of the current study is to identify and classify outcome measures currently used for the assessment of rehabilitation or assistive robot devices. We conducted a systematic review of the literature using PubMed, MEDLINE, CIRRIE, and Scopus databases for studies that assessed rehabilitation or assistive robot devices from 1980 through January 2016. In all, 31 articles met all inclusion criteria. Tailor-made questionnaires were the most commonly used tool at 66.7%, while the great majority (93.9%) of the studies used nonvalidated instruments. The study reveals the absence of a standard scale which makes it difficult to compare the results from different researchers. There is a great need, therefore, for a valid and reliable instrument to be available for use by the intended end users for the subjective assessment of robot devices. The study concludes by identifying two scales that have been validated in general assistive technology devices and could support the scope of subjective assessment in rehabilitation or assistive robots (however, with limited coverage) and a new one called PYTHEIA, recently published. The latter intends to close the gap and help researchers and developers to evaluate, assess, and produce products that satisfy the real needs of the end users.

  6. Assistive Devices for Children with Functional Impairments: Impact on Child and Caregiver Function

    Science.gov (United States)

    Henderson, Stacey; Skelton, Heather; Rosenbaum, Peter

    2008-01-01

    Functional impairments can limit a child's ability to participate in the experiences of childhood. This "deprivation" can, in turn, have a negative effect on such children's development, academic performance, and quality of life, as well as on the lives of their caregivers and families. Many adults use assistive devices to overcome functional…

  7. User Evaluation of the MOBOT Rollator Type Robotic Mobility Assistive Device

    Directory of Open Access Journals (Sweden)

    Yiannis Koumpouros

    2017-11-01

    Full Text Available In this paper, we report on the evaluation strategy and the results that were obtained from the final end-user evaluation process of an innovative robotic assistive device supporting mobility. More specifically, the paper deals with the evaluation of the MOBOT robotic rollator as regards to the system’s overall performance and its individual assistive characteristics and functionalities, as implemented in respect to (i the provided cognitive assistance, and (ii the adopted audio-gestural human-robot communication model. User evaluation was designed on the basis of an extensive survey of scales and methodologies widely reported in the relevant literature. The actual evaluation phase exploited the QUEST 2.0, ATDPA-Device Form, and PYTHEIA scales to measure the subjective satisfaction of the users. The PYTHEIA scale, in particular, was structured in order to fill the gaps that were identified during the study of previously existing tools for measuring assistive device user satisfaction. The scale was applied for the first time during the reported evaluation process. An analysis of the results showed that MOBOT was ranked very high by end users in all of the aspects addressed by the three employed assessment scales, thus providing significant evidence for positive acceptance of any industrialized outcome of the current prototype in the assistive robots market.

  8. Fine trabecularized carbon: ideal material and texture for percutaneous device system of permanent left ventricular assist device.

    Science.gov (United States)

    Tagusari, O; Yamazaki, K; Litwak, P; Kojima, A; Klein, E C; Antaki, J F; Watach, M; Gordon, L M; Kono, K; Mori, T; Koyanagi, H; Griffith, B P; Kormos, R L

    1998-06-01

    The development of a percutaneous artificial internal organ system requires a reliable biocompatible connection between the external environment and the inside of the human body. Such is necessary for the success of a permanent left ventricular assist device. However, the search for a satisfactory interface at the epidermal level has proven to be difficult. Carbon has been proposed for this application, but its texture does not typically promote ingrowth from surrounding tissue. We have therefore employed a new processing method to produce a fine trabecularized carbon implant. The method for preparing the implant involves infiltrating low temperature pyrolytic carbon into the surface of a carbon core which is wrapped with carbon fabric. This results in a tightly woven porous structure of carbon (carbon fiber diameter: 35-50 microm, maximal pore size >200 microm) with gradually increasing porosity from 15-75%. We implanted test samples percutaneously in a calf for in vivo histological evaluation. Thirty days after implantation epidermal downgrowth was minimal. Microscopic analysis revealed that a thin fibrous capsule surrounded the implant, and mature connective tissue with accompanying blood vessels filled the pores of the fine trabecularized carbon layer. From these results we suggest that fine trabecularized carbon is ideally suited for a percutaneous device system in a permanent left ventricular assist device.

  9. Ambient assisted living devices interoperability based on OSGi and the X73 standard.

    Science.gov (United States)

    Damas, Miguel; Pomares, Hector; Gonzalez, Sergio; Olivares, Alberto; Rojas, Ignacio

    2013-01-01

    The need for interoperability among devices is an issue of vital importance in current telemedicine systems. Although a completely standardized system is an ideal solution, most commercially available devices include their own software and communication protocols, which cause serious problems and hinder the application of a standard. Patients' telemonitoring at home requires a wide variety of biometric and ambient sensors and devices that usually present a set of very specific features and characteristics. The present article introduces a system based on the Open Services Gateway Initiative architecture, which offers plug-and-play connectivity of ambient assisted living devices. Using a data model inspired by the X73 standard, we describe a set of bundles that reduces the interoperability problem and allows the data stored in the platform to be independent from the connected devices.

  10. Physical assistance devices in complex motor skill learning: benefits of a self-controlled practice schedule.

    Science.gov (United States)

    Wulf, G; Toole, T

    1999-09-01

    This study examines the effects of a self-controlled use of physical assistance devices on learning a complex motor skill (i.e., producing slalom-type movements on a ski simulator). Physical assistance was provided by ski poles. One group of learners (self-control) was provided with the poles whenever they requested them, whereas another (yoked) group had no influence on the pole/no-pole schedule. While there were no group differences during the practice phase (Days 1 and 2), clear group differences emerged in the retention test without poles (Day 3). The self-control group produced significantly larger amplitudes than the yoked group. These results extend previous findings by showing learning advantages of the self-controlled use of physical assistance devices in complex motor skill learning.

  11. Heart Rate Detection Using Microsoft Kinect: Validation and Comparison to Wearable Devices

    Directory of Open Access Journals (Sweden)

    Ennio Gambi

    2017-08-01

    Full Text Available Contactless detection is one of the new frontiers of technological innovation in the field of healthcare, enabling unobtrusive measurements of biomedical parameters. Compared to conventional methods for Heart Rate (HR detection that employ expensive and/or uncomfortable devices, such as the Electrocardiograph (ECG or pulse oximeter, contactless HR detection offers fast and continuous monitoring of heart activities and provides support for clinical analysis without the need for the user to wear a device. This paper presents a validation study for a contactless HR estimation method exploiting RGB (Red, Green, Blue data from a Microsoft Kinect v2 device. This method, based on Eulerian Video Magnification (EVM, Photoplethysmography (PPG and Videoplethysmography (VPG, can achieve performance comparable to classical approaches exploiting wearable systems, under specific test conditions. The output given by a Holter, which represents the gold-standard device used in the test for ECG extraction, is considered as the ground-truth, while a comparison with a commercial smartwatch is also included. The validation process is conducted with two modalities that differ for the availability of a priori knowledge about the subjects’ normal HR. The two test modalities provide different results. In particular, the HR estimation differs from the ground-truth by 2% when the knowledge about the subject’s lifestyle and his/her HR is considered and by 3.4% if no information about the person is taken into account.

  12. A conceptual definition of quality of life with a left ventricular assist device: results from a qualitative study.

    Science.gov (United States)

    Sandau, Kristin E; Hoglund, Barbara A; Weaver, Carrie E; Boisjolie, Charlene; Feldman, David

    2014-01-01

    To develop a conceptual definition of quality of life (QoL) with a left ventricular assist device (LVAD). Conceptual and operational definitions of QoL with an LVAD are lacking. A grounded theory method was used. Adult, outpatient LVAD recipients (n = 11) participated twice in individual or paired interviews. A conceptual definition of QoL while living with an LVAD was established as: "Being well enough to do and enjoy day-to-day activities that are important to me." Participants described 5 important life domains consistent with QoL literature: physical, emotional, social, cognitive, and spiritual/meaning. However, participants identified unique concerns not addressed by generic or heart failure disease specific measures typically used in the LVAD population. Existing generic and heart-failure specific QoL measures are not adequate for understanding QoL among LVAD patients. Cognition and spiritual/meaning domains were significant; these need inclusion for comprehensive QoL assessment in the LVAD population. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Integration of augmented reality and assistive devices for post-stroke hand opening rehabilitation.

    Science.gov (United States)

    Luo, Xun; Kline, Tiffany; Fischer, Heidi; Stubblefield, Kathy; Kenyon, Robert; Kamper, Derek

    2005-01-01

    Impairment of hand function is prevalent among stroke survivors, motivating the search for effective rehabilitation therapy. Recent studies have suggested that for upper extremity functional recovery, repetitive training with virtual reality is helpful. Repetitive training can be facilitated with assistance from mechanical devices. Thus, we have developed a training environment that integrates augmented reality (AR) with assistive devices for post-stroke hand rehabilitation. The AR element of our environment utilizes head mounted display and virtual objects for reach-and-grasp task training. The assistive device consists of either a body-powered orthosis (BPO) or a pneumatic-powered device (PPD), both of which are incorporated into gloves. This environment can be easily set up and calibrated, is customizable for individual users, and requires active user participation. Additionally, it can be used with both real and virtual objects, as desired. We are currently conducting pilot case studies to assess ease of use and efficacy. At present, one stroke survivor from each of the three training conditions, AR-with-BPO, AR-with-PPD and AR-only (acting as the control), has completed the 6-week training paradigm. Preliminary findings suggest user acceptance of the technology and some potential for beneficial effects.

  14. A novel approach in extracorporeal circulation: individual, integrated, and interactive heart-lung assist (I3-Assist).

    Science.gov (United States)

    Wagner, Georg; Schlanstein, Peter; Fiehe, Sandra; Kaufmann, Tim; Kopp, Rüdger; Bensberg, Ralf; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Arens, Jutta

    2014-04-01

    Extracorporeal life support (ECLS) is a well-established technique for the treatment of different cardiac and pulmonary diseases, e.g., congenital heart disease and acute respiratory distress syndrome. Additionally, severely ill patients who cannot be weaned from the heart-lung machine directly after surgery have to be put on ECLS for further therapy. Although both systems include identical components, a seamless transition is not possible yet. The adaption of the circuit to the patients' size and demand is limited owing to the components available. The project I³-Assist aims at a novel concept for extracorporeal circulation. To better match the patient's therapeutic demand of support, an individual number of one-size oxygenators and heat exchangers will be combined. A seamless transition between cardiopulmonary bypass and ECLS will be possible as well as the exchange of components during therapy to enhance circuit maintenance throughout long-term support. Until today, a novel oxygenator and heat exchanger along with a simplified manufacturing protocol have been established. The first layouts of the unit to allow the spill- and bubble-free connection and disconnection of modules as well as improved cannulas and a rotational pump are investigated using computational fluid dynamics. Tests were performed according to current guidelines in vitro and in vivo. The test results show the feasibility and potential of the concept.

  15. Percutaneous Ventricular Restoration with a Partitioning Device for Ischemic Heart Failure Treatment.

    Science.gov (United States)

    Dhakal, Bishnu P; Oliveira, Guilherme H

    2017-04-01

    Percutaneous ventricular restoration with a ventricular partitioning device (VPD) is a novel minimally invasive procedure designed to restore the left ventricular (LV) shape by isolating the infarcted and aneurysmal LV apex from remainder of the cavity in heart failure patients with severely reduced LV ejection fraction. In this review, we perform an in-depth analysis of the design and purpose of the VPD and review the available clinical data, with special attention to hemodynamics, outcomes, and complications. PARACHUTE trials have shown >90% procedural success rate of VPD implant. Heart failure patients had improvement in hemodynamics (reduction in LV volumes and increase in LV ejection fraction) and functional status (6-min walking distance and quality of life scores) after the VPD implant. Optimal implant position is necessary to obtain a good clinical outcome. Percutaneous VPD implantation has thus far been a safe intervention capable of improving surrogate markers of heart failure but there is still a need to develop more durable devices with a long-lasting hemodynamics effect.

  16. Laminated Copper Nanocluster Incorporated Antioxidative Paper Device with RGB System-Assisted Signal Improvement

    Directory of Open Access Journals (Sweden)

    Chong-You Chen

    2018-02-01

    Full Text Available Paper-based analytical devices are an emerging class of lightweight and simple-to-use analytical platform. However, challenges such as instrumental requirements and chemical reagents durability, represent a barrier for less-developed countries and markets. Herein, we report an advanced laminated device using red emitting copper nanocluster and RGB digital analysis for signal improvement. Upon RGB system assistance, the device signal-to-background ratio and the calibration sensitivity are highly enhanced under a filter-free setup. In addition, the calibration sensitivity, limit of detection, and coefficient of determination are on par with those determined by instrumental fluorescence analysis. Moreover, the limitation of using oxidation-susceptible fluorescent nanomaterials is overcome by the introduction of protecting tape barriers, antioxidative sheets, and lamination enclosing. The robustness of device is highly advanced, and the durability is prolonged to more than tenfold.

  17. Interacting with and via mobile devices and mobile robots in an assisted living setting

    Directory of Open Access Journals (Sweden)

    Maria Dagioglou

    2015-05-01

    Full Text Available Using robotic home assistants as a platform for remote health monitoring offers several advantages, but also presents considerable challenges related to both the technical immaturity of home robotics and to user acceptance issues. In this paper we explore tablets and similar mobile devices as the medium of communication between robots and their users, presenting relevant current and planned research in humanrobot interaction that can help the telehealth community circumvent technical shortcomings, improve user acceptance, and maximize the quality of the data collected by robotic home assistants.

  18. Left ventricular dimension decrement index early after axial flow assist device implantation: A novel risk marker for late pump thrombosis.

    Science.gov (United States)

    Joyce, Emer; Stewart, Garrick C; Hickey, Maryclare; Coakley, Lara; Rivero, Jose M; Gosev, Igor; Givertz, Michael M; Couper, Gregory S; Mehra, Mandeep R

    2015-12-01

    It is increasingly recognized that pump thrombosis most likely represents the end stage of a complex interaction between the patient-pump interface. We hypothesized that early patient/pump mismatch, as manifested by suboptimal left ventricular (LV) unloading early after left ventricular assist device (LVAD) implantation, may be a harbinger of increased risk for later LVAD thrombosis. In 64 patients (59 ± 11 years old, 78% men, 44% destination therapy) discharged alive without thrombosis or other device malfunction after first HeartMate II LVAD implantation (between January 2011 and June 2014), LV dimensions in end diastole (LVIDd) and end systole (LVIDs) were compared between pre-implant and optimal set speed pre-discharge echocardiography. LV dimension decrement indices (pre-implant dimension - optimal set speed dimension ÷ pre-implant dimension × 100) for LVIDd [LVIDdDI] and LVIDs [LVIDsDI] were calculated. The incidence of pump thrombosis was 0.06 per patient year (n = 18, median time 8 [interquartile range 2, 17] months). Baseline characteristics including pre-operative LVIDd and LVIDs were similar between LVAD thrombosis and no thrombosis groups. After ventricular assist device implantation, set speed and other ramp parameters did not differ between groups. However, LVIDdDI (19 ± 13% vs 25 ± 11%, p = 0.04) and LVIDsDI (16 ± 16% vs 27 ± 13%, p = 0.008) were significantly lower in patients with later pump thrombosis. A cutoff value of ≤15% using receiver operating characteristic curve analysis was 83% sensitive for LVIDdDI and LVIDsDI for predicting pump thrombosis. Patients with LVIDdDI of >15% vs ≤15% were significantly more likely to be free of pump thrombosis over a median follow-up period of 15 (interquartile range 9, 26) months (log-rank test, p = 0.045). LV dimension decrement index at optimized speed setting on pre-discharge echocardiography is associated with LVAD thrombosis. Copyright © 2015 International Society for Heart and Lung

  19. The impact of mobility assistive technology devices on participation for individuals with disabilities.

    Science.gov (United States)

    Carver, Jordan; Ganus, Ashley; Ivey, Jon Mark; Plummer, Teresa; Eubank, Ann

    2016-08-01

    This study aims to address the gap in research and contribute to the body of knowledge on the perspectives assistive technology device users have toward their devices. Mixed methods were used to better understand the impact of mobility assistive technology devices (MATDs) on participation for individuals with disabilities. The Functional Mobility Assessment was administered in conjunction with two qualitative questions developed by the research team allowing participants to expound on the impact of their MATD experience. Participants were recruited online via the National Spinal Cord Injury Association website and in-person at Abilities Expo in Atlanta, Georgia, and the International Seating Symposium in Nashville, Tennessee. Results are consistent with findings from prior research regarding accessibility for individuals with disabilities. Corresponding findings were found in both the quantitative and qualitative data and are categorized into several major themes: environment (indoor and outdoor), surface heights, transportation, dependence, independence, quality of life and participation. Quantitative data from this study indicate that users of MATD are satisfied with the way in which their devices enable maneuvering indoors, while qualitative data suggest otherwise. Implications for healthcare practitioners are described and future recommendations are provided. Implications for Rehabilitation Healthcare professionals should advocate for proper mobility assistive technology devices (MATDs) for their patients in order to enable increased independence, safety and efficiency. Healthcare professionals must be cognizant of the impact of the environment and/or environmental barriers when prescribing MATD. Additional areas of interest for future research may include investigating the impact of MATD in association with date of onset of disability, according to diagnoses, or specific to length of time since acquiring the device.

  20. Towards a modified consumer haptic device for robotic-assisted fine-motor repetitive motion training.

    Science.gov (United States)

    Palsbo, Susan E; Marr, Deborah; Streng, Taylor; Bay, Brian K; Norblad, A Walter

    2011-01-01

    To develop, test and evaluate affordable haptic technology to provide robotic-assisted repetitive motion fine-motor training. A haptic computer/user interface was modified by adding a pantograph to hold a pen and to increase the haptic workspace. Custom software moves a pen attached to the device through prescribed three-dimensional (3D) stroke sequences to create two-dimensional glyphs. The pen's position is recorded in 3D coordinates at 1 kHz. Twenty-one healthy child volunteers were taught a standard handwriting curriculum in a group setting, two times per week for 45-60 min each session over 8 wks. The curriculum was supplemented by the device under the supervision of occupational therapy students. Outcomes were measured using the Evaluation Tool of Children's Handwriting (ETCH), and the Beery-Buktenica Developmental Test of visual-motor integration. Word legibility made significant gains on near point copying task (p=0.04; effect size=0.95). Letter legibility made no significant improvement. One healthy volunteer with illegible handwriting improved significantly on 8 of 14 ETCH measures. The children found the device engaging, but made several recommendations to redesign the pantograph and scribing movements. A consumer haptic device can be modified for robotic-assisted repetitive motion training for children. The device is affordable, portable, and engaging. It is safe for healthy volunteers. Objective time-stamped data offer the potential for telerehabilitation between a remote therapist and the school or home. © 2011 Informa UK, Ltd.

  1. Internal vacuum-assisted closure device in the swine model of severe liver injury

    Directory of Open Access Journals (Sweden)

    Everett Christopher B

    2012-12-01

    Full Text Available Abstract Objectives The authors present a novel approach to nonresectional therapy in major hepatic trauma utilizing intraabdominal perihepatic vacuum assisted closure (VAC therapy in the porcine model of Grade V liver injury. Methods A Grade V injury was created in the right lobe of the liver in a healthy pig. A Pringle maneuver was applied (4.5 minutes total clamp time and a vacuum assisted closure device was placed over the injured lobe and connected to suction. The device consisted of a perforated plastic bag placed over the liver, followed by a 15 cm by 15cm VAC sponge covered with a nonperforated plastic bag. The abdomen was closed temporarily. Blood loss, cardiopulmonary parameters and bladder pressures were measured over a one-hour period. The device was then removed and the animal was euthanized. Results Feasibility of device placement was demonstrated by maintenance of adequate vacuum suction pressures and seal. VAC placement presented no major technical challenges. Successful control of ongoing liver hemorrhage was achieved with the VAC. Total blood loss was 625 ml (20ml/kg. This corresponds to class II hemorrhagic shock in humans and compares favorably to previously reported estimated blood losses with similar grade liver injuries in the swine model. No post-injury cardiopulmonary compromise or elevated abdominal compartment pressures were encountered, while hepatic parenchymal perfusion was maintained. Conclusion These data demonstrate the feasibility and utility of a perihepatic negative pressure device for the treatment of hemorrhage from severe liver injury in the porcine model.

  2. Internal vacuum-assisted closure device in the swine model of severe liver injury

    Science.gov (United States)

    2012-01-01

    Objectives The authors present a novel approach to nonresectional therapy in major hepatic trauma utilizing intraabdominal perihepatic vacuum assisted closure (VAC) therapy in the porcine model of Grade V liver injury. Methods A Grade V injury was created in the right lobe of the liver in a healthy pig. A Pringle maneuver was applied (4.5 minutes total clamp time) and a vacuum assisted closure device was placed over the injured lobe and connected to suction. The device consisted of a perforated plastic bag placed over the liver, followed by a 15 cm by 15cm VAC sponge covered with a nonperforated plastic bag. The abdomen was closed temporarily. Blood loss, cardiopulmonary parameters and bladder pressures were measured over a one-hour period. The device was then removed and the animal was euthanized. Results Feasibility of device placement was demonstrated by maintenance of adequate vacuum suction pressures and seal. VAC placement presented no major technical challenges. Successful control of ongoing liver hemorrhage was achieved with the VAC. Total blood loss was 625 ml (20ml/kg). This corresponds to class II hemorrhagic shock in humans and compares favorably to previously reported estimated blood losses with similar grade liver injuries in the swine model. No post-injury cardiopulmonary compromise or elevated abdominal compartment pressures were encountered, while hepatic parenchymal perfusion was maintained. Conclusion These data demonstrate the feasibility and utility of a perihepatic negative pressure device for the treatment of hemorrhage from severe liver injury in the porcine model. PMID:23217091

  3. Development of a Risk Assessment Assistance Tool for Robotic Care Devices.

    Science.gov (United States)

    Homma, Keiko; Matsumoto, Osamu

    2017-01-01

    Aiming to eliminate a labor shortage caused by the aging of society, many kinds of service robots are under development. Nursing care for the elderly is considered as a typical application of service robots, especially in Japan. Elderly care robots or robotic care device must be designed with safety, but not a few manufacturers are inexperienced in designing and manufacturing them on the basis of safety. In this paper, we introduce a risk assessment assistance tool for robotic care device targeted for inexperienced manufacturers of risk assessment.

  4. A Numerical Analysis of Phononic-Assisted Control of Ultrasound Waves in Acoustofluidic Device

    DEFF Research Database (Denmark)

    Moiseyenko, Rayisa; Bruus, Henrik

    2015-01-01

    diffractors, which can be introduced in acoustofluidic structures. These diffractors can be applied in the design of efficient resonant cavities, directional sound waves for new types of particle sorting methods, or acoustically controlled deterministic lateral displacement. The PnC-diffractor-based devices...... and streaming has received much attention, since it relies solely on mechanical properties such as particle size and contrast in density and compressibility. We present a theoretical study of phononic-assisted control of ultrasound waves in acoustofluidic devices. We propose the use of phononic crystal...

  5. Identification of tasks performed by stroke patients using a mobility assistive device

    DEFF Research Database (Denmark)

    Hester, Todd; Sherrill, Delsey M; Hamel, Mathieu

    2006-01-01

    of these devices. In this study, we propose the use of wearable sensors to identify tasks performed by stroke patients with a mobility assistive device. Subjects performed ten tasks with a three-axis accelerometer attached to their ankle and a neural network was trained to identify the task being performed....... Results from 15 stroke patients indicated that these motor tasks can be reliably identified with a median sensitivity of 90 % at a median specificity of 95%. These results indicate that it is possible to use a single module with a three-axis accelerometer attached to the ankle to reliably identify motor...

  6. Prospective Randomized Evaluation of Implantable Cardioverter-Defibrillator Programming in Patients With a Left Ventricular Assist Device.

    Science.gov (United States)

    Richardson, Travis D; Hale, Leslie; Arteaga, Christopher; Xu, Meng; Keebler, Mary; Schlendorf, Kelly; Danter, Matthew; Shah, Ashish; Lindenfeld, JoAnn; Ellis, Christopher R

    2018-02-23

    Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy-programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra-conservative ICD programming strategy in patients with LVAD affects ICD shocks. Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra-conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra-conservative group 16% of patients experienced at least one shock compared with 21% in the control group ( P =0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT-ON but this was not statistically significant: 10% of patients with CRT-ON (n=21) versus 38% with CRT-OFF (n=20) received shocks ( P =0.08). An ultra-conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  7. Activated Hemostatic Biomarkers in Patients with Implanted Left Ventricle Assist Devices: Are Heparin and/or Clopidogrel Justified?

    Science.gov (United States)

    Pacholewicz, Jerzy; Kuliczkowski, Wiktor; Kaczmarski, Jacek; Zakliczyński, Michał; Garbacz, Marcin; Zembala, Marian; Serebruany, Victor

    2015-01-01

    Adequate anticoagulation represents a major problem for left ventricle assist device (LVAD) utilization in patients awaiting heart transplantation as well as for regeneration of the native heart. The proper management of hemostatic abnormalities during LVAD support may improve survival by reducing the incidence of hemorrhagic and/or thromboembolic complications. A 40-year-old man with implanted pulsatile LVAD due to dilated cardiomyopathy received aspirin and warfarin. The patient underwent serial weekly monitoring of hemostatic biomarkers including international normalization ratio, prothrombin time, prothrombin activity, activated partial thromboplastin time, fibrinogen, D-dimer, platelet aggregation induced by adenosine diphosphate and arachidonic acid, platelet count, and mean platelet volume. The external pump was exchanged three times - twice because of a clot formation in the blood chamber of the pump, and once according to the standard protocol. LVAD use was consistently associated with enhanced adenosine diphosphate-induced platelet aggregation independent from the timing of clot formation or external pump exchange. Among coagulation indices, increased D-dimer holds predictive value for clot formation. The fibrinogen level peaked before the first pump exchange and was twice as high than the average values. Gradual improvement in exercise capacity was observed 2 years after implantation, after which the patient underwent a controlled stress test in the stop mode of the LVAD and the device was successfully explanted. Serial assessment of hemostatic biomarkers may benefit and triage LVAD patients. Consistent platelet activation during long-term LVAD may justify the addition of clopidogrel, while high D-dimer and/or elevated fibrinogen may indicate adding heparin to the conventional antithrombotic regimen. Randomized evidence is needed to test such a hypothesis. © 2015 S. Karger AG, Basel.

  8. How are service users instructed to measure home furniture for provision of minor assistive devices?

    Science.gov (United States)

    Atwal, Anita; Mcintyre, Anne; Spiliotopoulou, Georgia; Money, Arthur; Paraskevopulos, Ioannis

    2017-02-01

    Measurements play a vital role in providing devices that meet the individual needs of users. There is increasing evidence of devices being abandoned. The reasons for this are complex but one key factor that plays a role in non-use of equipment is the lack of fit between the device, environment and person. In addition, the abandonment of devices can be seen as a waste of public money. The aim of this paper is to examine the type, the readability, and the content of existing guidance in relation to measuring home furniture. An online national survey involving health and social care trusts in the UK. We conducted a synthesis of leaflets associated with measurement of furniture to identify existing guidance. The content and readability of this guidance was then evaluated. From the 325 responses received, 64 therapists reported using guidance. From the 13 leaflets that were analysed, 8 leaflets were found to meet Level 3 Adult Literacy Standards (age 9-11). There were differences in the way in which the measurement of furniture items occurred within the leaflets with no measurement guidance reported for baths. There is a need to standardize guidance to ensure that measurements are reliable. Implications for Rehabilitation Our research has highlighted the need to confirm and agree measurement techniques for home furniture in the provision of assistive devices. Inaccurate guidance can lead to abandonment of devices. Inaccurate guidance could prevent service users from not participating within the self-assessment process for devices.

  9. Identification of differentially expressed transcripts and pathways in blood one week and six months following implant of left ventricular assist devices.

    Directory of Open Access Journals (Sweden)

    Adam Mitchell

    Full Text Available INTRODUCTION: Continuous-flow left ventricular assist devices (LVADs are an established therapy for patients with end-stage heart failure. The short- and long-term impact of these devices on peripheral blood gene expression has not been characterized, and may provide insight into the molecular pathways mediated in response to left ventricular remodeling and an improvement in overall systemic circulation. We performed RNA sequencing to identify genes and pathways influenced by these devices. METHODS: RNA was extracted from blood of 9 heart failure patients (8 male prior to LVAD implantation, and at 7 and 180 days postoperatively. Libraries were sequenced on an Illumina HiSeq2000 and sequences mapped to the human Ensembl GRCh37.67 genome assembly. RESULTS: A specific set of genes involved in regulating cellular immune response, antigen presentation, and T cell activation and survival were down-regulated 7 days after LVAD placement. 6 months following LVAD placement, the expression levels of these genes were significantly increased; yet importantly, remained significantly lower than age and sex-matched samples from healthy controls. CONCLUSIONS: In summary, this genomic analysis identified a significant decrease in the expression of genes that promote a healthy immune response in patients with heart failure that was partially restored 6 months following LVAD implant.

  10. Does reduced movement restrictions and use of assistive devices affect rehabilitation outcome after total hip replacement?

    DEFF Research Database (Denmark)

    Mikkelsen, Lone Ramer; Petersen, Annemette Krintel; Søballe, Kjeld

    2014-01-01

    ). This group was compared to patients included the following 3 months with less restricted hip movement and use of assistive devices according to individual needs (unrestricted group). Questionnaires on function, pain, quality of life (HOOS), anxiety (HADS), working status and patient satisfaction were.......004). Return to work 6 weeks after THR for the unrestricted group compared to restricted group was: 53% versus 32% (P=0.045). No significant differences between groups in pain, symptoms, quality of life, anxiety/depression, hip dislocations and patient satisfaction. CONCLUSION: This study showed slightly...... slower recovery in patient-reported function after reduction in movement restrictions and use of assistive devices, but the difference was eliminated after 6 weeks. Reduced movement restrictions did not affect the other patient-reported outcomes and led to earlier return to work. CLINICAL REHABILITATION...

  11. In vivo assessment of hemocompatibility of a ventricular assist device in healthy swine

    OpenAIRE

    Sacristán,Catarina; Escobedo,Carlos R.; Bojalil, Rafael; Izaguirre,Raúl A.; Cortina,Evelyn; Aranda,Alberto; Catrip,Jorge; Lesprón,Ma del Carmen; Springall, Rashidi; Sacristán,Emilio

    2010-01-01

    Objective: To assess the hemocompatible performance of a novel implantable pneumatic ventricular assist device (VAD, Innovamédica, México) in healthy swine. The aim of this pilot study was first, to determine if short-term VAD implantation elicited a remarkable inflammatory response above that expected from surgical trauma; and second, to assess if heparinized or passivated VAD coatings, in combination with systemic anticoagulant or antiaggregant therapies, modified the VAD's hemocompatible p...

  12. The Application of Vacuum-Assisted Closure Device in the Management of Empyema Necessitans

    Directory of Open Access Journals (Sweden)

    Yasser Aljehani

    2016-01-01

    Full Text Available Vacuum-assisted closure (VAC is gaining popularity in the management of many types of acute and chronic wounds. The use of VAC devices in thoracic surgery is limited, but it appears to be promising in complex cases of empyema thoraces. We report a case of empyema necessitans, in which VAC was used to achieve complete wound healing after open drainage which was communicating with the pleural space.

  13. Application of Vacuum-Assisted Closure Device in Management of Postpneumonectomy Empyema

    Science.gov (United States)

    Sohn, Suk Ho; Choi, Se Hoon; Kim, Young Tae

    2013-01-01

    A 57-year-old man was diagnosed with lung cancer and underwent pneumonectomy and mediastinal lymph node dissection. He was discharged without acute complications, but on a regular outpatient follow-up, he was readmitted with postpneumonectomy empyema. He was successfully treated with a vacuum-assisted closure device and for 1 year period of outpatient follow-up, there was no recurrence of empyema or lung cancer. PMID:23614105

  14. Assistive devices alter gait patterns in Parkinson disease: advantages of the four-wheeled walker.

    Science.gov (United States)

    Kegelmeyer, Deb A; Parthasarathy, Sowmya; Kostyk, Sandra K; White, Susan E; Kloos, Anne D

    2013-05-01

    Gait abnormalities are a hallmark of Parkinson's disease (PD) and contribute to fall risk. Therapy and exercise are often encouraged to increase mobility and decrease falls. As disease symptoms progress, assistive devices are often prescribed. There are no guidelines for choosing appropriate ambulatory devices. This unique study systematically examined the impact of a broad range of assistive devices on gait measures during walking in both a straight path and around obstacles in individuals with PD. Quantitative gait measures, including velocity, stride length, percent swing and double support time, and coefficients of variation were assessed in 27 individuals with PD with or without one of six different devices including canes, standard and wheeled walkers (two, four or U-Step). Data were collected using the GAITRite and on a figure-of-eight course. All devices, with the exception of four-wheeled and U-Step walkers significantly decreased gait velocity. The four-wheeled walker resulted in less variability in gait measures and had less impact on spontaneous unassisted gait patterns. The U-Step walker exhibited the highest variability across all parameters followed by the two-wheeled and standard walkers. Higher variability has been correlated with increased falls. Though subjects performed better on a figure-of-eight course using either the four-wheeled or the U-Step walker, the four-wheeled walker resulted in the most consistent improvement in overall gait variables. Laser light use on a U-Step walker did not improve gait measures or safety in figure-of-eight compared to other devices. Of the devices tested, the four-wheeled-walker offered the most consistent advantages for improving mobility and safety. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Rubbing salt into wounds: hypertonic saline to assist with volume removal in heart failure.

    Science.gov (United States)

    Liszkowski, Mark; Nohria, Anju

    2010-09-01

    Traditionally accepted management strategies for patients with heart failure include sodium and fluid restriction, neurohormonal blockade, and the use of loop diuretics to achieve and maintain euvolemia. Despite continued advances in medical and device therapy, fluid management remains a significant problem in patients with the cardiorenal syndrome (manifested as diuretic resistance and worsening renal function with more aggressive attempts at volume removal). This article examines the counterintuitive use of hypertonic saline as a potential therapy to facilitate diuresis in patients with decompensated heart failure and diuretic resistance. Low-volume hypertonic saline administration offsets counterproductive neurohormonal upregulation, transiently improves hemodynamics, and promotes renal sodium excretion with accompanied net water loss and preservation of renal function. This "new" therapeutic tool should be explored further as an adjunct to current medical therapies in the management of patients with refractory volume overload.

  16. Therapeutic bodily assistive devices and paralympic athlete expectations in winter sport.

    Science.gov (United States)

    Wolbring, Gregor

    2012-01-01

    To ascertain the impact of therapeutic bodily assistive devices that enable beyond-the-normal body abilities on sport in general and the Paralympics and Olympics in particular. Cross-sectional survey. Online. Members of the National Council on Rehabilitation Education (United States). Distribution of online survey link to membership. The survey used a combination of 37 simple yes or no, Likert scale, and opinion rating scale questions. This article is based on 4 of the 37 questions that focus on the impact of therapeutic enhancements on various aspects of sport. Whether respondents felt that there is an impact of therapeutic bodily assistive devices that enable beyond-the-normal body abilities on the participation of people with disabilities in sport of all levels and the self-identity of athletes with disabilities. Secondary outcome measure was what the respondents felt the impact may be. The respondents indicated that therapeutic bodily assistive devices, which enable beyond-the-normal body abilities, will have an impact on participation of people with disabilities in sport at all levels and on the self-identity of athletes with disabilities. Given the result that the respondents felt that therapeutic enhancements will impact various aspects of sport, it may be prudent to initiate a broader discourse around therapeutic enhancement and to revise codes of ethics so that they give guidance on this topic.

  17. Stability analysis of electrical powered wheelchair-mounted robotic-assisted transfer device.

    Science.gov (United States)

    Wang, Hongwu; Tsai, Chung-Ying; Jeannis, Hervens; Chung, Cheng-Shiu; Kelleher, Annmarie; Grindle, Garrett G; Cooper, Rory A

    2014-01-01

    The ability of people with disabilities to live in their homes and communities with maximal independence often hinges, at least in part, on their ability to transfer or be transferred by an assistant. Because of limited resources and the expense of personal care, robotic transfer assistance devices will likely be in great demand. An easy-to-use system for assisting with transfers, attachable to electrical powered wheelchairs (EPWs) and readily transportable, could have a significant positive effect on the quality of life of people with disabilities. We investigated the stability of our newly developed Strong Arm, which is attached and integrated with an EPW to assist with transfers. The stability of the system was analyzed and verified by experiments applying different loads and using different system configurations. The model predicted the distributions of the system's center of mass very well compared with the experimental results. When real transfers were conducted with 50 and 75 kg loads and an 83.25 kg dummy, the current Strong Arm could transfer all weights safely without tip-over. Our modeling accurately predicts the stability of the system and is suitable for developing better control algorithms to enhance the safety of the device.

  18. Objective and perceptual comparisons of two bluetooth hearing aid assistive devices.

    Science.gov (United States)

    Clark, Jackie L; Pustejovsky, Carmen; Vanneste, Sven

    2017-08-01

    With the advent of Bluetooth technology, many of the assistive listening devices for hearing have become manufacturer specific, with little objective information about the performance provided. Thirty native English-speaking adults (mean age 29.8) with normal hearing were tested pseudo-randomly with two major hearing aid manufacturers' proprietary Bluetooth connectivity devices paired to the accompanying manufacturer's specific hearing aids. Sentence recognition performance was objectively measured for each system with signals transmitted via a land-line to the same iPhone in two conditions. There was a significant effect of participant's performance according to listening condition. There was no significant effect between device manufacturers according to listening condition, but there was a significant effect in participant's perception of "quality of sound". Despite differences in signal transmission for each devise, when worn by participants both the systems performed equally. In fact, participants expressed personal preferences for specific technology that was largely due to their perceived quality of sound while listening to recorded signals. While further research is necessary to investigate other measures of benefit for Bluetooth connectivity devices, preliminary data suggest that in order to ensure comfort and compatibility, not only should objective measures of the patient benefit be completed, but also assessing the patient's perception of benefit is equally important. Implications for Rehabilitation All professionals who work with individuals with hearing loss, become aware of the differences in the multiple choices for assistive technology readily available for hearing loss. With the ever growing dispensing of Bluetooth connectivity devices coupled to hearing aids, there is an increased burden to determine whether performance differences could exist between manufacturers. There is a growing need to investigate other measures of benefit for Bluetooth

  19. Sociodemographic and clinical profile of children with congenital heart disease assisted at a hospital institution

    Directory of Open Access Journals (Sweden)

    Mirna Albuquerque Frota

    2014-06-01

    Full Text Available Objective: To characterize the sociodemographic and clinical profile of children with congenital heart disease assisted at a hospital institution. Methods: A descriptive, crosssectional study conducted in the pediatric cardiology outpatient clinic of a hospital in Fortaleza, CE, Brazil, in the period from March to August 2012. It comprised a nonrandom convenience sample of 80 parents of children with heart disease aged 5 to 12 years. Information was obtained from primary data of medical records and through questionnaires covering the parent’s sociodemographic characteristics, family data and the children’s clinical aspects. Results: Regarding socioeconomic data, 77 (96.2% caregivers were female, 50 (62.5% were married or in a stable relationship, 39 (48.7% had 10-12 years of formal education, and 69 (82.6% reported a household income between 1 and 2 minimum wages. In the sample of children studied, 43 (53.8% were female. The median age of the children was 8.4 years, ranging from 5-13 years. As to the age at the heart disease diagnosis, 44 (55% occurred under the age of 6 months, regardless of the type of cardiopathy. It was detected that 19 (23.75% were related to the disease. Conclusion: Children’s caregivers were predominantly their mothers, with low income and satisfactory schooling. Early diagnosis was predominant, mainly among the children with cyanotic cardiopathy. doi:10.5020/18061230.2014.p239

  20. The evolution and benefit of device therapy in patients listed for heart transplant.

    Science.gov (United States)

    Vandenberk, Bert; Hinderks, Mark; Voros, Gabor; Garweg, Christophe; Vanhaecke, Johan; Willems, Rik

    2017-03-09

    The latest 2015 ESC Guidelines on the prevention of sudden cardiac death make a Class IIa recommendation for ICD implantation in patients listed for heart transplantation. This recommendation was based on expert consensus in view of the sparsity of data. All patients listed for heart transplantation at the University Hospitals of Leuven from 2002 until 2014 were studied retrospectively. Exclusion criteria were age HR 4.38, 95%CI 2.11-9.01), a history of stroke (HR 2.95, 95%CI 1.61-5.40), older age (HR 1.03, 95%CI 1.01-1.05) and a worse renal function (HR 1.15, 95%CI 1.00-1.33). The time on the waiting list for heart transplantation significantly increased together with an increased use of device therapy in this population. The proportion of patients reaching transplant remained unchanged. This patient group is prone to life-threatening arrhythmias and the use of an ICD may improve survival.

  1. RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna.

    Science.gov (United States)

    Murphy, Olive H; Borghi, Alessandro; Bahmanyar, Mohammad Reza; McLeod, Christopher N; Navaratnarajah, Manoraj; Yacoub, Magdi; Toumazou, Christofer

    2014-06-01

    The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted.

  2. Shape optimization of pulsatile ventricular assist devices using FSI to minimize thrombotic risk

    Science.gov (United States)

    Long, C. C.; Marsden, A. L.; Bazilevs, Y.

    2014-10-01

    In this paper we perform shape optimization of a pediatric pulsatile ventricular assist device (PVAD). The device simulation is carried out using fluid-structure interaction (FSI) modeling techniques within a computational framework that combines FEM for fluid mechanics and isogeometric analysis for structural mechanics modeling. The PVAD FSI simulations are performed under realistic conditions (i.e., flow speeds, pressure levels, boundary conditions, etc.), and account for the interaction of air, blood, and a thin structural membrane separating the two fluid subdomains. The shape optimization study is designed to reduce thrombotic risk, a major clinical problem in PVADs. Thrombotic risk is quantified in terms of particle residence time in the device blood chamber. Methods to compute particle residence time in the context of moving spatial domains are presented in a companion paper published in the same issue (Comput Mech, doi: 10.1007/s00466-013-0931-y, 2013). The surrogate management framework, a derivative-free pattern search optimization method that relies on surrogates for increased efficiency, is employed in this work. For the optimization study shown here, particle residence time is used to define a suitable cost or objective function, while four adjustable design optimization parameters are used to define the device geometry. The FSI-based optimization framework is implemented in a parallel computing environment, and deployed with minimal user intervention. Using five SEARCH/ POLL steps the optimization scheme identifies a PVAD design with significantly better throughput efficiency than the original device.

  3. Achieving Identity-Based Cryptography in a Personal Digital Assistant Device

    Directory of Open Access Journals (Sweden)

    L. Martínez-Ramos

    2011-12-01

    Full Text Available Continuous technological advances have allowed that mobile devices, such as Personal Digital Assistants (PDAs, can execute sophisticated applications that more often than not must be equipped with a layer of security that should include the confidentiality and the authentication services within its repertory. Nevertheless, when compared against front-end computing devices, most PDAs are still seen as constrained devices with limited processing and storage capabilities.In order to achieve Identity-Based Cryptography (IBC, which was an open problem proposed by Adi Shamir in 1984, Bonehand Franklin presented in Crypto 2001, a solution that uses bilinear pairings as its main building block. Since then, IBC hasbecome an active area of investigation where many efficient IBC security protocols are proposed year after year. In this paper,we present a cryptographic application that allows the secure exchange of documents from a Personal Digital Assistant (PDAthat is wirelessly connected to other nodes. The architecture of our application is inspired by the traditional PGP (Pretty GoodPrivacy email security protocol. Our application achieves identity-based authentication and confidentiality functionalities at the 80-bit security level through the usage of a cryptographic library that was coded in C++. Our library can perform basic primitives such as bilinear pairings defined over the binary field and the ternary field , as well as other required primitivesknown as map-to-point hash functions. We report the timings achieved by our application and we show that they compare wellagainst other similar works published in the open literature.

  4. [Mechanical cardiac-assist devices in ST segment elevation myocardial infarction].

    Science.gov (United States)

    Spaulding, C

    2015-12-01

    A 49-year-old woman was admitted for an anterior ST segment elevation myocardial infarction (STEMI). At hospital arrival, she presented with cardiogenic shock. An immediate coronary angiogram showed an occluded ostial left anterior descending artery. During percutaneous coronary intervention (PCI), ventricular fibrillation occurred requiring multiple electrical counter-shocks. The coronary artery was opened during cardiopulmonary resuscitation and two drug-eluting stents were implanted. At the end of the procedure, an Impella CP® mechanical cardiac-assist device was inserted. Rapid and marked improvement in the hemodynamic status was noted in the following days. The Impella CP® was withdrawn after five days and the patient was discharged two weeks later. Despite limited data, mechanical cardiac assistance is recommended in cardiogenic shock. Several devices are currently available; the choice of the system is based on the clinical presentation and the experience of each center. The Impella CP® is a microaxial pump which is inserted percutaneously and delivers up to 3.5L/min of continuous flow. In cardiogenic shock due to STEMI, this device allows temporary support while awaiting left ventricular recovery after primary PCI. Copyright © 2015. Published by Elsevier SAS.

  5. Right ventricular dysfunction following continuous flow left ventriccular assist device placement in 51 patients: predicators and outcomes

    Directory of Open Access Journals (Sweden)

    Neragi-Miandoab Siyamek

    2012-06-01

    Full Text Available Abstract Background Right ventricular (RV dysfunction following implantation of a left ventricular assist device (LVAD is a serious condition and is associated with increased mortality. Methods The aim of the study is to investigate the significance of pre-existing RV dysfunction, tricuspid valve (TV insufficiency, and the severity of septal deviation following LVAD implantation on RV dysfunction, as well as the outcome and short-term complications in 51 patients from June 2006 to August 2010. Student t test was used to compare the data and estimate the p value. Results Mean age was 55.1 ± 13, with a male to female ratio of 3.25. The 30-day mortality was 13.7% (7/51 patients, and the overall mortality was 23.5% (12/51 patients. Meanwhile, 21 patients (21/51; 41.2% have undergone orthotopic heart transplantation. The mean time of support was 314.5±235 days with a median of 240 days at the time of closing this study. Echocardiographic evaluation of RV function pre- and post-implantation of an LVAD demonstrated septal deviation towards the left ventricle in immediate postoperative phase, which correlated with acute RV dysfunction (p = 0.002. Preoperative RV dysfunction was a significant predictor of postoperative right heart dysfunction following implantation of an LVAD (p = 0.001. Conclusion Preoperative RV dysfunction is a predictor of RV failure in LVAD patients. The adjustment of septal deviation through gradual increase of the LVAD flow can prevent the acute RV dysfunction following LVAD placement.

  6. Association between cell-derived microparticles and adverse events in patients with nonpulsatile left ventricular assist devices.

    Science.gov (United States)

    Nascimbene, Angelo; Hernandez, Ruben; George, Joggy K; Parker, Anita; Bergeron, Angela L; Pradhan, Subhashree; Vijayan, K Vinod; Civitello, Andrew; Simpson, Leo; Nawrot, Maria; Lee, Vei-Vei; Mallidi, Hari R; Delgado, Reynolds M; Dong, Jing Fei; Frazier, O H

    2014-05-01

    Continuous-flow left ventricular assist devices (LVADs) expose blood cells to high shear stress, potentially resulting in the production of microparticles that express phosphatidylserine (PS+) and promote coagulation and inflammation. In this prospective study, we attempted to determine whether PS+ microparticle levels correlate with clinical outcomes in LVAD-supported patients. We enrolled 20 patients undergoing implantation of the HeartMate II LVAD (Thoratec Corp, Pleasanton, CA) and 10 healthy controls who provided reference values for the microparticle assays. Plasma was collected before LVAD implantation, at discharge, at the 3-month follow-up, and when an adverse clinical event occurred. We quantified PS+ microparticles in the plasma using flow cytometry. During the study period, 8 patients developed adverse clinical events: ventricular tachycardia storm in 1, non-ST-elevation myocardial infarction in 2, arterial thrombosis in 2, gastrointestinal bleeding in 2, and stroke in 3. Levels of PS+ microparticles were higher in patients at baseline than in healthy controls (2.11% ± 1.26% vs 0.69% ± 0.46%, p = 0.007). After LVAD implantation, patient PS+ microparticle levels increased to 2.39% ± 1.22% at discharge and then leveled to 1.97% ± 1.25% at the 3-month follow-up. Importantly, levels of PS+ microparticles were significantly higher in patients who developed an adverse event than in patients with no events (3.82% ± 1.17% vs 1.57% ± 0.59%, p < 0.001), even though the 2 patient groups did not markedly differ in other clinical and hematologic parameters. Our results suggest that an elevation of PS+ microparticle levels may be associated with adverse clinical events. Thus, measuring PS+ microparticle levels in LVAD-supported patients may help identify patients at increased risk for adverse events. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  7. Endoscopic Evaluation and Management of Gastrointestinal Bleeding in Patients with Ventricular Assist Devices

    Directory of Open Access Journals (Sweden)

    Marty M. Meyer

    2012-01-01

    Full Text Available The optimal diagnostic approach and yield for gastrointestinal bleeding (GIB in patients with ventricular assist devices (VAD are unknown. We explored the etiology of bleeding and yield of upper and lower endoscopy, balloon-assisted enteroscopy, and video capsule endoscopy in the evaluation of GIB in patients with VADs. Methods. All VAD patients with overt gastrointestinal bleeding and drop in hematocrit from April 1, 2000 to July 31, 2008 were retrospectively reviewed. The endoscopic evaluation of each episode was recorded. Overall yield of EGD, colonoscopy, balloon-assisted, and video capsule endoscopy were evaluated. Results. Thirty-six bleeding episodes occurred involving 20 patients. The site of GIB was identified in 32/36 episodes (88.9%, and the etiology of bleeding was determined in 30/36 cases (83.3%. Five VAD patients underwent VCE. The VCE exams demonstrated a high yield with 80% of exams identifying the etiology of GIB. Endoscopic intervention was successful in 8/9 attempts. No adverse events were recorded. Two patients required surgical intervention for GIB. Conclusion. Upper, lower, video capsule, and balloon-assisted enteroscopies are safe and demonstrate a high yield in the investigation of gastrointestinal bleeding in VAD patients. Medical centers caring for VAD patients should employ a standardized protocol to optimize endoscopic evaluation and intervention.

  8. Wireless sEMG-Based Body-Machine Interface for Assistive Technology Devices.

    Science.gov (United States)

    Fall, Cheikh Latyr; Gagnon-Turcotte, Gabriel; Dube, Jean-Francois; Gagne, Jean Simon; Delisle, Yanick; Campeau-Lecours, Alexandre; Gosselin, Clement; Gosselin, Benoit

    2017-07-01

    Assistive technology (AT) tools and appliances are being more and more widely used and developed worldwide to improve the autonomy of people living with disabilities and ease the interaction with their environment. This paper describes an intuitive and wireless surface electromyography (sEMG) based body-machine interface for AT tools. Spinal cord injuries at C5-C8 levels affect patients' arms, forearms, hands, and fingers control. Thus, using classical AT control interfaces (keypads, joysticks, etc.) is often difficult or impossible. The proposed system reads the AT users' residual functional capacities through their sEMG activity, and converts them into appropriate commands using a threshold-based control algorithm. It has proven to be suitable as a control alternative for assistive devices and has been tested with the JACO arm, an articulated assistive device of which the vocation is to help people living with upper-body disabilities in their daily life activities. The wireless prototype, the architecture of which is based on a 3-channel sEMG measurement system and a 915-MHz wireless transceiver built around a low-power microcontroller, uses low-cost off-the-shelf commercial components. The embedded controller is compared with JACO's regular joystick-based interface, using combinations of forearm, pectoral, masseter, and trapeze muscles. The measured index of performance values is 0.88, 0.51, and 0.41 bits/s, respectively, for correlation coefficients with the Fitt's model of 0.75, 0.85, and 0.67. These results demonstrate that the proposed controller offers an attractive alternative to conventional interfaces, such as joystick devices, for upper-body disabled people using ATs such as JACO.

  9. The Role of Subjective Well-Being in Co-Designing Open-Design Assistive Devices; design case study

    NARCIS (Netherlands)

    De Couvreur, L.; Dejonghe, W.; Detand, J.; Goossens, R.

    2013-01-01

    In this paper we explore the role of subjective well-being within the process of making together a personalized assistive device. Through a process of social product adaptation, assistive artifacts become part of occupational therapy and co-evolve with clients. Personal digital fabrication tools

  10. Physics and engineering aspects of cell and tissue imaging systems: microscopic devices and computer assisted diagnosis.

    Science.gov (United States)

    Chen, Xiaodong; Ren, Liqiang; Zheng, Bin; Liu, Hong

    2013-01-01

    The conventional optical microscopes have been used widely in scientific research and in clinical practice. The modern digital microscopic devices combine the power of optical imaging and computerized analysis, archiving and communication techniques. It has a great potential in pathological examinations for improving the efficiency and accuracy of clinical diagnosis. This chapter reviews the basic optical principles of conventional microscopes, fluorescence microscopes and electron microscopes. The recent developments and future clinical applications of advanced digital microscopic imaging methods and computer assisted diagnosis schemes are also discussed.

  11. Vasodilatory Shock After Ventricular Assist Device Placement: A Bench to Bedside Review.

    Science.gov (United States)

    Baer, John; Stoops, Shea; Flynn, Brigid

    2016-01-01

    With more than 2000 ventricular assist devices (VAD) placed annually in the United States, understanding postoperative management is important. One of the most common postoperative morbidities encountered with VAD implantation is vasodilatory shock. The mechanisms for this phenomenon are numerous and include cellular and hormonal aberrancies unique to the VAD recipient. Management of vasodilatory shock in VAD patients needs to be undertaken with an understanding of the side effects associated with each treatment, especially the effects on the right ventricle and pulmonary vasculature. This article focuses on the incidence, the pathogenesis, the consequences, and the management of vasodilatory shock in the postoperative VAD patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System.

    Science.gov (United States)

    Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori

    2013-01-01

    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

  13. An optimal controller for an electric ventricular-assist device: theory, implementation, and testing

    Science.gov (United States)

    Klute, G. K.; Tasch, U.; Geselowitz, D. B.

    1992-01-01

    This paper addresses the development and testing of an optimal position feedback controller for the Penn State electric ventricular-assist device (EVAD). The control law is designed to minimize the expected value of the EVAD's power consumption for a targeted patient population. The closed-loop control law is implemented on an Intel 8096 microprocessor and in vitro test runs show that this controller improves the EVAD's efficiency by 15-21%, when compared with the performance of the currently used feedforward control scheme.

  14. Improvement of survival rate in patients with cardiogenic shock by using nonpulsatile and pulsatile ventricular assist device.

    Science.gov (United States)

    Minami, K; el-Banayosy, A; Posival, H; Seggewiss, H; Murray, E; Körner, M M; Körfer, R

    1992-12-01

    Between January 1988 and January 1992, 65 patients (pts) had a ventricle assist device (VAD) inserted in our clinic. In 24 pts a VAD was applied because of primarily unsuccessful weaning from cardiopulmonary bypass (Group A). In a further 24 pts (Group B) a VAD was installed for the therapy of refractive cardiogenic shock (CS) after initially successful cardiac surgery (n = 21) and after acute myocardial infarction (n = 3). Twelve pts were bridged to heart transplantation (Group C) and five had a VAD inserted for various other reasons (Group D). In 36 (55.4%) of the total 65 pts a nonpulsatile VAD (Biomedicus 540) was used: 10 in Group A; 20 in B, 3 in C and 3 in D. In 29 pts (44.6%) a pulsatile VAD (Abiomed BVS 5000) was used: 14 in Group A, 4 in B, 9 in C and 2 in D. Weaning rate and long-term survival rates were 50% and 46% respectively in Group A and 38% and 42% in Group B. Seven pts from Group C were transplanted and six are long-term survivors. Two pts (40%) in Group D were discharged from hospital. Major postoperative complications were bleeding (46%), thromboembolism (14%), multiple organ failure (11%), renal failure (11%), arterial embolism (4.6%), sepsis (3%). The results indicate that application of a VAD can be recommended in pts with postcardiotomy CS to allow recovery of cardiac function and in pts with irreversible ventricular damage as bridging to HTX.

  15. Exertional Angina Due To Fused Aortic Bioprosthesis During Left Ventricular Assist Device Support: Two Cases and Review of the Literature.

    Science.gov (United States)

    Bonios, Michael J; Selzman, Craig H; Gilbert, Edward M; McKellar, Stephen H; Koliopoulou, Antigoni; Strege, Jennifer L; Nativi, Jose N; Fang, James C; Stehlik, Josef; Drakos, Stavros G

    We present the case of two patients with idiopathic dilated cardiomyopathy and moderate aortic valve regurgitation that were treated with a bioprosthetic valve at the time of the left ventricular assist device (LVAD) implantation. A few months later, patients revealed partial recovery in the left ventricle systolic function. Both patients, during the LVAD turndown protocol, reported the onset of chest pain. The transthoracic echocardiography revealed the presence of a new transaortic pressure gradient. We confirmed the presence of a fused bioprosthetic valve by further performing a transesophageal echocardiogram and a left and right heart catheterization. Replacement of aortic valve at the time of an LVAD implantation constitutes a challenging case. Although a mechanical valve is contraindicated due to the increased thromboembolic risk, selecting a bioprosthetic valve increases the risk of valve leaflets fusion. The consequences of this phenomenon should be acknowledged in LVAD patients undergoing aortic valve replacement with a bioprosthetic, especially under the view of LVAD explantation for those revealing myocardial recovery under mechanical unloading.

  16. Superior performance of continuous over pulsatile flow ventricular assist devices in the single ventricle circulation: A computational study.

    Science.gov (United States)

    Schmidt, Tyler; Rosenthal, David; Reinhartz, Olaf; Riemer, Kirk; He, Fei; Hsia, Tain-Yen; Marsden, Alison; Kung, Ethan

    2017-02-08

    This study compares the physiological responses of systemic-to-pulmonary shunted single ventricle patients to pulsatile and continuous flow ventricular assist devices (VADs). Performance differences between pulsatile and continuous flow VADs have been clinically observed, but the underlying mechanism remains poorly understood. Six systemic-to-pulmonary shunted single ventricle patients (mean BSA=0.30m(2)) were computationally simulated using a lumped-parameter network tuned to match patient specific clinical data. A first set of simulations compared current clinical implementation of VADs in single ventricle patients. A second set modified pulsatile flow VAD settings with the goal to optimize cardiac output (CO). For all patients, the best-case continuous flow VAD CO was at least 0.99L/min greater than the optimized pulsatile flow VAD CO (p=0.001). The 25 and 50mL pulsatile flow VADs exhibited incomplete filling at higher heart rates that reduced CO as much as 9.7% and 37.3% below expectations respectively. Optimization of pulsatile flow VAD settings did not achieve statistically significant (p<0.05) improvement to CO. Results corroborate clinical experience that continuous flow VADs produce higher CO and superior ventricular unloading in single ventricle patients. Impaired filling leads to performance degradation of pulsatile flow VADs in the single ventricle circulation. Published by Elsevier Ltd.

  17. Low-cost assistive device for hand gesture recognition using sEMG

    Science.gov (United States)

    Kainz, Ondrej; Cymbalák, Dávid; Kardoš, Slavomír.; Fecil'ak, Peter; Jakab, František

    2016-07-01

    In this paper a low-cost solution for surface EMG (sEMG) signal retrieval is presented. The principal goal is to enable reading the temporal parameters of muscles activity by a computer device, with its further processing. Paper integrates design and deployment of surface electrodes and amplifier following the prior researches. Bearing in mind the goal of creating low-cost solution, the Arduino micro-controller was utilized for analog-to-digital conversion and communication. The software part of the system employs support vector machine (SVM) to classify the EMG signal, as acquired from sensors. Accuracy of the proposed solution achieves over 90 percent for six hand movements. Proposed solution is to be tested as an assistive device for several cases, involving people with motor disabilities and amputees.

  18. Concept and first experimental results of a new ferromagnetic assist device for extra-aortic counterpulsation.

    Science.gov (United States)

    Starck, Christoph T; Becker, Jakob; Fuhrer, Roland; Sündermann, Simon; Stark, Jan Wendelin; Falk, Volkmar

    2014-01-01

    Based on a ferromagnetic silicone cuff for extra-aortic counterpulsation, a new assist device concept was developed. The driving force is generated by an external magnetic field, which leads to contraction of a soft magnetic cuff. The force generation capacity of the device was tested in a silicone aorta model. Magnetic elastomers can be constructed through dispersion of micro- or nanoparticles in polymer matrices and were designed to act as soft actuators. Two magnetically active silicone cuffs were produced with a nanomagnet loading of 250 wt% (Cuff 1) and a micromagnet loading of 67 wt% (Cuff 2). The magnetic cuffs were applied on a silicone aorta model and contracted against hydrostatic pressure. A full contraction of Cuff 1 was possible against a maximal hydrostatic pressure of 30 cmH₂O (22 mmHg) at a magnetic flux density of 0.4 T (Tesla) and 65 cmH₂O (48 mmHg) at a magnetic flux density of 1.2 T. A 50% contraction of Cuff 2 was possible against a maximal hydrostatic pressure of 80 cmH₂O (59 mmHg) at a magnet-cuff-distance (MCD) of 0 cm. At MCDs of 1 and 2 cm a 50% contraction was possible against 33 cmH₂O (24 mmHg) and 10 cmH₂O (7 mmHg), respectively. Combining the advantages of magnetic elastomers with the principle of extra-aortic counterpulsation in a new assist device concept avoids the need for anticoagulation (no contact with bloodstream). With regard to the magnetic principle of action, no intra- to extracorporeal connection is needed. More experimental work is needed to further increase the force generated by the silicone cuff and to transfer the device concept into an in vivo setting.

  19. Wireless photoplethysmographic device for heart rate variability signal acquisition and analysis.

    Science.gov (United States)

    Reyes, Ivan; Nazeran, Homer; Franco, Mario; Haltiwanger, Emily

    2012-01-01

    The photoplethysmographic (PPG) signal has the potential to aid in the acquisition and analysis of heart rate variability (HRV) signal: a non-invasive quantitative marker of the autonomic nervous system that could be used to assess cardiac health and other physiologic conditions. A low-power wireless PPG device was custom-developed to monitor, acquire and analyze the arterial pulse in the finger. The system consisted of an optical sensor to detect arterial pulse as variations in reflected light intensity, signal conditioning circuitry to process the reflected light signal, a microcontroller to control PPG signal acquisition, digitization and wireless transmission, a receiver to collect the transmitted digital data and convert them back to their analog representations. A personal computer was used to further process the captured PPG signals and display them. A MATLAB program was then developed to capture the PPG data, detect the RR peaks, perform spectral analysis of the PPG data, and extract the HRV signal. A user-friendly graphical user interface (GUI) was developed in LabView to display the PPG data and their spectra. The performance of each module (sensing unit, signal conditioning, wireless transmission/reception units, and graphical user interface) was assessed individually and the device was then tested as a whole. Consequently, PPG data were obtained from five healthy individuals to test the utility of the wireless system. The device was able to reliably acquire the PPG signals from the volunteers. To validate the accuracy of the MATLAB codes, RR peak information from each subject was fed into Kubios software as a text file. Kubios was able to generate a report sheet with the time domain and frequency domain parameters of the acquired data. These features were then compared against those calculated by MATLAB. The preliminary results demonstrate that the prototype wireless device could be used to perform HRV signal acquisition and analysis.

  20. Phantom-based evaluation method for surgical assistance devices in minimally invasive cochlear implantation

    Science.gov (United States)

    Lexow, G. Jakob; Kluge, Marcel; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S.

    2017-03-01

    Several research groups have proposed individual solutions for surgical assistance devices to perform minimally invasive cochlear implantation. The main challenge is the drilling of a small bore hole from the surface of the skull to the inner ear at submillimetric accuracy. Each group tested the accuracy of their device in their respective test bench or in a small number of temporal bone specimens. This complicates the comparison of the different approaches. Thus, a simple and inexpensive phantom based evaluation method is proposed which resembles clinical conditions. The method is based on half-skull phantoms made of bone-substitute material - optionally equipped with an artificial skin replica to include skin incision within the evaluation procedure. Anatomical structures of the temporal bone derived from segmentations using clinical imaging data are registered into a computer tomographic scan of the skull phantom and used for the planning of the drill trajectory. Drilling is performed with the respective device under conditions close to the intraoperative setting. Evaluation of accuracy can either be performed through postoperative imaging or by means of added targets on the inside of the skull model. Two different targets are proposed: simple reference marks only for measuring the accuracy of the device and a target containing a scala tympani model for evaluation of the complete workflow including the insertion of the electrode carrier. Experiments using the presented method take place under reproducible conditions thus allowing the comparison of the different approaches. In addition, artificial phantoms are easier to obtain and handle than human specimens.

  1. Investigating the Efficacy of a Computerized Prompting Device to Assist Children with Autism Spectrum Disorder with Activities of Daily Living

    Science.gov (United States)

    Bimbrahw, Justin; Boger, Jennifer; Mihailidis, Alex

    2012-01-01

    Learning to perform self-care skills can pose a major challenge for children with Autism Spectrum Disorder (ASD) as well as the parents and caregivers who support them. The computerized device described in this paper has been used by children with ASD and their carers to autonomously assist with self-care activities. The device uses computer…

  2. Estimating Heart Rate, Energy Expenditure, and Physical Performance With a Wrist Photoplethysmographic Device During Running.

    Science.gov (United States)

    Parak, Jakub; Uuskoski, Maria; Machek, Jan; Korhonen, Ilkka

    2017-07-25

    Wearable sensors enable long-term monitoring of health and wellbeing indicators. An objective evaluation of sensors' accuracy is important, especially for their use in health care. The aim of this study was to use a wrist-worn optical heart rate (OHR) device to estimate heart rate (HR), energy expenditure (EE), and maximal oxygen intake capacity (VO2Max) during running and to evaluate the accuracy of the estimated parameters (HR, EE, and VO2Max) against golden reference methods. A total of 24 healthy volunteers, of whom 11 were female, with a mean age of 36.2 years (SD 8.2 years) participated in a submaximal self-paced outdoor running test and maximal voluntary exercise test in a sports laboratory. OHR was monitored with a PulseOn wrist-worn photoplethysmographic device and the running speed with a phone GPS sensor. A physiological model based on HR, running speed, and personal characteristics (age, gender, weight, and height) was used to estimate EE during the maximal voluntary exercise test and VO2Max during the submaximal outdoor running test. ECG-based HR and respiratory gas analysis based estimates were used as golden references. OHR was able to measure HR during running with a 1.9% mean absolute percentage error (MAPE). VO2Max estimated during the submaximal outdoor running test was closely similar to the sports laboratory estimate (MAPE 5.2%). The energy expenditure estimate (n=23) was quite accurate when HR was above the aerobic threshold (MAPE 6.7%), but MAPE increased to 16.5% during a lighter intensity of exercise. The results suggest that wrist-worn OHR may accurately estimate HR during running up to maximal HR. When combined with physiological modeling, wrist-worn OHR may be used for an estimation of EE, especially during higher intensity running, and VO2Max, even during submaximal self-paced outdoor recreational running.

  3. Control of a Pediatric Pulsatile Ventricular Assist Device: A Hybrid Cardiovascular Model Study.

    Science.gov (United States)

    Ferrari, Gianfranco; Di Molfetta, Arianna; Zieliński, Krzysztof; Fresiello, Libera; Górczyńska, Krystyna; Pałko, Krzysztof Jakub; Darowski, Marek; Amodeo, Antonio; Kozarski, Maciej

    2017-12-01

    The aim of this work is to study pediatric pneumatic ventricle (PVAD) performance, versus VAD rate (VADR) and native heart rate (HR) ratio Rr (VADR/HR). The study uses a hybrid model of the cardiovascular system (HCS). HCS consists of a computational part (a lumped parameter model including left and right ventricles, systemic and pulmonary arterial and venous circulation) interfaced to a physical part. This permits the connection of a VAD (15 mL PVAD). Echocardiographic and hemodynamic data of a pediatric patient (average weight 14.3 kg, HR 100 bpm, systemic pressure 75/44 mm Hg, CO 1.5 L/min) assisted apically with asynchronous PVAD were used to set up a basal condition in the model. After model tuning, the assistance was started, setting VAD parameters (ejection and filling pressures, systole duration) to completely fill and empty the PVAD. The study was conducted with constant HR and variable VADR (50-120, step 10, bpm). Experiments were repeated for two additional patients' HRs, 90 and 110 bpm and for two values of systemic arterial resistance (Ras ) and Emax . Experimental data were collected and stored on disk. Analyzed data include average left and right ventricular volumes (LVV, RVV), left ventricular flow (LVF), VAD flow (VADF), and total cardiac output (COt). Data were analyzed versus Rr. LVV and RVV are sensitive to Rr and a left ventricular unloading corresponds in general to a right ventricular loading. In the case of asynchronous assistance, frequency beats are always present and the beat rate is equal to the difference between HR and VADR. In the case of pulsatile asynchronous LVAD assistance, VADR should be chosen to minimize frequency beat effects and right ventricular loading and to maximize left ventricular unloading. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  4. Modification of self-concept in patients with a left-ventricular assist device: an initial exploration.

    Science.gov (United States)

    Marcuccilli, Linda; Casida, Jesus; Peters, Rosalind M

    2013-09-01

    To explore how patients with left-ventricular assist devices (LVAD) meet the health-deviation requisite of modifying self-concept to accept this form of treatment and restore normalcy. LVAD are becoming a standard option to improve the quality of life for patients with advanced heart failure. Past research focused on technology issues and survival rates, but limited research has addressed the effect of LVADs on patients' perceptions of self. Orem's theory of self-care provides a framework to investigate how patients manage threats to self-concept to safely live with such a device. Hermeneutic phenomenology based on van Manen's method. Data were collected using semi-structured interviews. Data saturation was achieved with nine participants (seven men; two women), 31-70 years of age who lived with a LVAD at home for at least three months. Thematic analysis was ongoing, and final themes were consensually validated. Two themes constructed from the data were consistent with the requisite of modifying self-concept. First, Having a LVAD means living. Participants described they 'feel alive again', and they 'had the rest of [their] lives that they didn't have before'. The second theme: A desire to be 'normal' in public, arose from participants descriptions of how the LVAD brought unwanted attention to them and that their appearance was 'shocking' to others. Participants accepted the LVAD as necessary to live making it easier for them to modify their self-concept and accept the changes to their bodies and daily lives. Attaining a sense of normalcy was more difficult in public and required additional lifestyle modifications. Findings advance self-care knowledge in LVAD management and can heighten nurses' awareness about self-concept as a vital component for maintenance of health and well-being. © 2013 Blackwell Publishing Ltd.

  5. Real time heart rate variability assessment from Android smartphone camera photoplethysmography: Postural and device influences.

    Science.gov (United States)

    Guede-Fernandez, F; Ferrer-Mileo, V; Ramos-Castro, J; Fernandez-Chimeno, M; Garcia-Gonzalez, M A

    2015-01-01

    The aim of this paper is to present a smartphone based system for real-time pulse-to-pulse (PP) interval time series acquisition by frame-to-frame camera image processing. The developed smartphone application acquires image frames from built-in rear-camera at the maximum available rate (30 Hz) and the smartphone GPU has been used by Renderscript API for high performance frame-by-frame image acquisition and computing in order to obtain PPG signal and PP interval time series. The relative error of mean heart rate is negligible. In addition, measurement posture and the employed smartphone model influences on the beat-to-beat error measurement of heart rate and HRV indices have been analyzed. Then, the standard deviation of the beat-to-beat error (SDE) was 7.81 ± 3.81 ms in the worst case. Furthermore, in supine measurement posture, significant device influence on the SDE has been found and the SDE is lower with Samsung S5 than Motorola X. This study can be applied to analyze the reliability of different smartphone models for HRV assessment from real-time Android camera frames processing.

  6. Modelo experimental para treinamento com dispositivo de assistência ventricular pulsátil Experimental ventricular assist device to maintain cardiocirculatory conditions

    Directory of Open Access Journals (Sweden)

    Maurício Galantier

    1995-09-01

    Full Text Available Os dispositivos de Assistência Ventricular (D A V têm sido utilizados para permitir a manutenção de condições cardiocirculatórias em dois tipos de situações: 1- Como ponte para transplante cardíaco em paciente candidato e que, na espera de doador apropriado, tem suas condições cardiocirculatórias muito deterioradas. 2- Como suporte circulatório em situações agudas em que se prevê uma possível recuperação funcional do coração, como em miocardites agudas, miocardiopatia puerperal, falência miocárdica pós cardiotomia, rejeição aguda pós transplante cardíaco etc. Entre os vários dispositivos utilizados, o modelo descrito por Pierce-Donachy, desenvolvido pela Thoratec Laboratories Corporation, consiste em aparelho de fluxo pulsátil, pneumático, externo, podendo ser usado como suporte uni ou biventricular. O ventrículo artificial é acionado por um módulo que permite vários ajustes manuais ou mesmo automáticos para melhor adequação às diferentes condições clínicas do paciente. O treinamento para utilização do dispositivo implica na integração de vários setores, como cirurgiões, intensivistas, enfermeiras, biomédicos e eletrotécnicos, necessitando laboratório especializado, com o uso de animais de maior porte, de custo elevado e manuseio complicado, dificultando a repetição freqüente dos experimentos. Os autores desenvolveram um modelo experimental, constituído por um coração bovino conectado pelo átrio esquerdo e pela aorta a um circuito de circulação extracorpórea. Através de técnica cirúrgica padronizada, são instaladas as cânulas apropriadas; as mesmas são conectadas ao ventrículo artificial e este ao módulo de acionamento. Com este modelo podese, de maneira simples, didática e reprodutível, efetuar o treinamento de aspectos técnicos de implante, manuseio de módulo de acionamento e simulação de situações clínicas e emergenciaisThe Ventricular Assist Devices (V A D have

  7. Estimating Accuracy at Exercise Intensities: A Comparative Study of Self-Monitoring Heart Rate and Physical Activity Wearable Devices

    OpenAIRE

    Dooley, Erin E.; Golaszewski, Natalie M; Bartholomew, John B.

    2017-01-01

    Background Physical activity tracking wearable devices have emerged as an increasingly popular method for consumers to assess their daily activity and calories expended. However, whether these wearable devices are valid at different levels of exercise intensity is unknown. Objective The objective of this study was to examine heart rate (HR) and energy expenditure (EE) validity of 3 popular wrist-worn activity monitors at different exercise intensities. Methods A total of 62 participants (fema...

  8. Utilization of assistive devices for students with disabilities in the public schools

    Directory of Open Access Journals (Sweden)

    Carolina Bastos Plotegher

    2013-04-01

    Full Text Available Introduction: Assistive technology is an area of expanding knowledge in Brazil. Its use in school can help students with disabilities in performing important tasks to participate in different activities. Objectives: to report the experience of using assistive devices in the academic achievement of students with disabilities included in the regular school system of the municipality of Sao Carlos, state of Sao Paulo. Method: it was developed from an extension project conducted in 2010. Thirteen students with various types of disabilities participated in the project. The interventions were based on the School Function Assessment with the teachers to know the students’ difficulties. The students were also observed performing school tasks. Results: Forty-seven adaptations were made: thickeners, rings for zippers, slants, communication boards, non-slip mats, among others. Besides the adjustments, orientation regarding use of the devices was provided for teachers and persons responsible for the students. Conclusion: we believe that the project benefited the students, because it produced higher academic achievement and provided better school conditions for their school inclusion. For the undergraduate students of Occupational Therapy, the project enabled the dealing with real issues of inclusion and school interventions, thus approaching theory to practice.

  9. Environmental barriers to participation and facilitators for use of three types of assistive technology devices.

    Science.gov (United States)

    Widehammar, Cathrine; Lidström, Helene; Hermansson, Liselotte

    2017-08-07

    The aim was to compare the presence of environmental barriers to participation and facilitators for assistive technology (AT) use and study the relation between barriers and AT use in three different AT devices. A cross-sectional survey was conducted. Inclusion criteria were ≥one year of experience as a user of myoelectric prosthesis (MEP), powered mobility device (PMD), or assistive technology for cognition (ATC) and age 20-90 years. Overall, 156 participants answered the Swedish version of the Craig Hospital Inventory of Environmental Factors and a study-specific questionnaire on facilitating factors. Non-parametric tests were used for comparisons. Barriers to participation were lowest in MEP users (md=0.12; p>0.001), and highest in ATC users (md=1.56; p>0.001) with the least support for AT use (p>0.001 - p=0.048). A positive correlation between fewer barriers and higher use of MEP was seen (r=0.30, p=0.038). The greatest barriers to participation were Natural environment, Surroundings and Information, and the most support came from relatives and professionals. Support, training and education are vital in the use of AT. These factors may lead to a more sustained and prolonged use of AT and may enable increased participation. Future research should focus on interventions that meet the needs of people with cognitive disabilities.

  10. A Wearable Robotic Device Based on Twisted String Actuation for Rehabilitation and Assistive Applications

    Directory of Open Access Journals (Sweden)

    Mohssen Hosseini

    2017-01-01

    Full Text Available The preliminary experimental study toward the implementation of an arm rehabilitation device based on a twisted string actuation module is presented. The actuation module is characterized by an integrated force sensor based on optoelectronic components. The adopted actuation system can be used for a wide set of robotic applications and is particularly suited for very compact, light-weight, and wearable robotic devices, such as wearable rehabilitation systems and exoskeletons. Thorough presentation and description of the proposed actuation module as well as the basic force sensor working principle are illustrated and discussed. A conceptual design of a wearable arm assistive system based on the proposed actuation module is presented. Moreover, the actuation module has been used in a simple assistive application, in which surface-electromyography signals are used to detect muscle activity of the user wearing the system and to regulate the support action provided to the user to reduce his effort, showing in this way the effectiveness of the approach.

  11. An integrated array of microfluidic oxygenators as a neonatal lung assist device: in vitro characterization and in vivo demonstration.

    Science.gov (United States)

    Rochow, Niels; Manan, Asmaa; Wu, Wen-I; Fusch, Gerhard; Monkman, Shelley; Leung, Jennifer; Chan, Emily; Nagpal, Dipen; Predescu, Dragos; Brash, John; Selvaganapathy, Ponnambalam Ravi; Fusch, Christoph

    2014-10-01

    A miniaturized oxygenator device that is perfused like an artificial placenta via the umbilical vessels may have significant potential to save the lives of newborns with respiratory insufficiency. Recently we presented the concept of an integrated modular lung assist device (LAD) that consists of stacked microfluidic single oxygenator units (SOUs) and demonstrated the technical details and operation of SOU prototypes. In this article, we present a LAD prototype that is designed to accommodate the different needs of term and preterm infants by permitting changing of the number of parallel-stacked microfluidic SOUs according to the actual body weight. The SOUs are made of polydimethylsiloxane, arranged in parallel, and connected though 3D-printed polymeric interconnects to form the LAD. The flow characteristics and the gas exchange properties were tested in vitro using human blood. We found that the pressure drop of the LAD increased linearly with flow rate. Gas exchange rates of 2.4-3.8 μL/min/cm(2) (0.3-0.5 mL/kg/min) and 6.4-10.1 μL/min/cm(2) (0.8-1.3 mL/kg/min) for O2 and CO2 , respectively, were achieved. We also investigated protein adsorption to provide preliminary information on the need for application of anticoagulant coating of LAD materials. Albumin adsorption, as measured by gold staining, showed that surface uptake was evenly distributed and occurred at the monolayer level (>0.2 μg/cm(2) ). Finally, we also tested the LAD under in vivo conditions using a newborn piglet model (body weight 1.65-2.0 kg). First, the effect of an arteriovenous bypass via a carotid artery-to-jugular vein shortcut on heart rate and blood pressure was investigated. Heart rate and mean arterial blood pressure remained stable for extracorporeal flow rates of up to 61 mL/kg/min (101 mL/min). Next, the LAD was connected to umbilical vessels (maximum flow rate of 24 mL/min [10.4 mL/kg/min]), and O2 gas exchange was measured under hypoxic conditions (Fi O2

  12. Cross-cultural adaptation of the assistive technology device - Predisposition assessment (ATD PA) for use in Brazil (ATD PA Br).

    Science.gov (United States)

    Alves, Ana Cristina de Jesus; Matsukura, Thelma Simões; Scherer, Marcia J

    2017-02-01

    The purpose of this study is to conduct a cross-cultural adaptation of the Assistive Technology Device Predisposition Assessment (ATD PA) for use in Brazil. The selection of the Assistive Technology Device Predisposition Assessment (ATD PA) was determined by previous literature reviews of articles published in 2014 and 2016 in six databases with the terms "assistive device" or "assistive technology" or "self-help device" combined with "evidence-based practice" or "framework" or "measurement scale" or "model and outcome assessment". This review indicated that the conceptual model of Assistive Technology (AT) most discussed in the literature was the Matching Person and Technology (MPT) model, and this finding determined the selection of ATD PA as an assessment within the MPT portfolio of measures. The procedures for cross-cultural adaptation were as follows: Equivalence of Concept, Semantic and Operational. Five experts were asked to translate 725 items and these translations were evaluated and a high level of agreement was demonstrated. The Portuguese version, Avaliação de Tecnologia Assistiva - Predisposição ao Uso - ATD PA Br, was derived from the original version in English (ATD PA). The ATD PA Br will support professionals and people with disabilities in Brazil to better select AT devices according to the clients' needs. Implications for rehabilitation Provides a systematic way of selecting assistive technology devices for the use of individuals with disabilities according to the Brazilian reality. A systematic way of selecting the assistive technology that can help decrease the abandonment of the assistive technology use. The use of the Matching Person and Technology theorical model and of the assessment ATD PA Br is essential to guide the researches and clinical practice in Brazil.

  13. Electric poling-assisted additive manufacturing process for PVDF polymer-based piezoelectric device applications

    Science.gov (United States)

    Lee, ChaBum; Tarbutton, Joshua A.

    2014-09-01

    This paper presents a new additive manufacturing (AM) process to directly and continuously print piezoelectric devices from polyvinylidene fluoride (PVDF) polymeric filament rods under a strong electric field. This process, called ‘electric poling-assisted additive manufacturing or EPAM, combines AM and electric poling processes and is able to fabricate free-form shape piezoelectric devices continuously. In this process, the PVDF polymer dipoles remain well-aligned and uniform over a large area in a single design, production and fabrication step. During EPAM process, molten PVDF polymer is simultaneously mechanically stresses in-situ by the leading nozzle and electrically poled by applying high electric field under high temperature. The EPAM system was constructed to directly print piezoelectric structures from PVDF polymeric filament while applying high electric field between nozzle tip and printing bed in AM machine. Piezoelectric devices were successfully fabricated using the EPAM process. The crystalline phase transitions that occurred from the process were identified by using the Fourier transform infrared spectroscope. The results indicate that devices printed under a strong electric field become piezoelectric during the EPAM process and that stronger electric fields result in greater piezoelectricity as marked by the electrical response and the formation of sharper peaks at the polar β crystalline wavenumber of the PVDF polymer. Performing this process in the absence of an electric field does not result in dipole alignment of PVDF polymer. The EPAM process is expected to lead to the widespread use of AM to fabricate a variety of piezoelectric PVDF polymer-based devices for sensing, actuation and energy harvesting applications with simple, low cost, single processing and fabrication step.

  14. Short periodic applications of the vacuum-assisted closure device cause an extended tissue response in the diabetic mouse model.

    Science.gov (United States)

    Scherer, Sandra Saja; Pietramaggiori, Giorgio; Mathews, Jasmine C; Orgill, Dennis P

    2009-11-01

    The vacuum-assisted closure device is a widely used mechanical modulator of wound healing; however, the optimal time kinetics of application have not been determined. The objective of the study was to optimize the kinetics of vacuum-assisted closure application. Full-thickness wounds in seven diabetic mice per study group were treated with either an occlusive dressing alone, the vacuum-assisted closure device for 6 or 12 hours, or the vacuum-assisted closure device periodically for 4 hours every other day or continuously for 7 days. Wound closure and tissue response were evaluated by macroscopic, histologic, and immunohistochemical analyses on day 7. Wound closure was significantly faster after short initial vacuum-assisted closure (6-hour and 12-hour groups) when compared with continuous treatment. Increased granulation tissue formation was seen in the 12-hour group (2.4-fold increase) and in those treated periodically for 4 hours every other day (3.2-fold increase) compared with the dressing-alone controls. Significant stimulation of cell proliferation was seen after all vacuum-assisted closure patterns (3.6- to 5.3-fold increase), whereas angiogenesis was augmented only after the device was applied for either three times for 4 hours (4.3-fold) or continuously (4.7-fold) when compared with dressing-treated wounds. Treatment three times for 4 hours showed a superior angiogenic effect also when compared with short initial applications (6-hour and 12-hour groups). Short vacuum-assisted closure treatment induced an extended biological response in the wound. A total of 12 hours of periodically applied vacuum-assisted closure reached a similar wound tissue response as continuously applied vacuum-assisted closure for 7 days. These findings suggest new clinical approaches for mechanical wound-healing devices.

  15. Self-Organizing Wearable Device Platform for Assisting and Reminding Humans in Real Time

    Directory of Open Access Journals (Sweden)

    Yu Jin Park

    2016-01-01

    Full Text Available Most older persons would prefer “aging in my place,” that is, to remain in good health and live independently in their own home as long as possible. For assisting the independent living of older people, the ability to gather and analyze a user’s daily activity data would constitute a significant technical advance, enhancing their quality of life. However, the general approach based on centralized server has several problems such as the usage complexity, the high price of deployment and expansion, and the difficulty in identifying an individual person. To address these problems, we propose a wearable device platform for the life assistance of older persons that automatically records and analyzes their daily activity without intentional human intervention or a centralized server (i.e., cloud server. The proposed platform contains self-organizing protocols, Delay-Tolerant Messaging system, knowledge-based analysis and alerting for daily activities, and a hardware platform that provides low power consumption. We implemented a prototype smart watch, called Personal Activity Assisting and Reminding (PAAR, as a testbed for the proposed platform, and evaluated the power consumption and the service time of example scenarios.

  16. Pulmonary Valve Opening With Two Rotary Left Ventricular Assist Devices for Biventricular Support.

    Science.gov (United States)

    Wu, Eric L; Nestler, Frank; Kleinheyer, Matthias; Stevens, Michael C; Pauls, Jo P; Fraser, John F; Gregory, Shaun D

    2018-01-01

    Right ventricular failure is a common complication associated with rotary left ventricular assist device (LVAD) support. Currently, there is no clinically approved long-term rotary right ventricular assist device (RVAD). Instead, clinicians have implanted a second rotary LVAD as RVAD in biventricular support. To prevent pulmonary hypertension, the RVAD must be operated by either reducing pump speed or banding the outflow graft. These modes differ in hydraulic performance, which may affect the pulmonary valve opening (PVO) and subsequently cause fusion, valvular insufficiency, and thrombus formation. This study aimed to compare PVO with the RVAD operated at reduced speed or with a banded outflow graft. Baseline conditions of systemic normal, hypo, and hypertension with severe biventricular failure were simulated in a mock circulation loop. Biventricular support was provided with two rotary VentrAssist LVADs with cardiac output restored to 5 L/min in banded outflow and reduced speed conditions, and systemic and pulmonary vascular resistances (PVR) were manipulated to determine the range of conditions that allowed PVO without causing left ventricular suction. Finally, RVAD sine wave speed modulation (±550 rpm) strategies (co- and counter-pulsation) were implemented to observe the effect on PVO. For each condition, outflow banding had higher PVR (97 ± 20 dyne/s/cm5 higher) for when the pulmonary valve closed compared to reduced speed. In addition, counter-pulsation demonstrated greater PVO than co-pulsation and constant speed. For the purpose of reducing the risks of pulmonary valve insufficiency, fusion, and thrombotic event, this study recommends a RVAD with a steeper H-Q gradient by banding and further exploration of RVAD speed modulation. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. Acute Effects of a Therapeutic Mobility Device on Physical Activity and Heart Rate in Children with Down Syndrome

    Science.gov (United States)

    Hauck, Janet L.; Ulrich, Dale A.

    2015-01-01

    Purpose: The purpose of this feasibility study was to provide an opportunity to increase physical activity (PA) and heart rate (HR) for children with Down syndrome (DS) during unstructured group exercise utilizing a riding device called the Power Pumper®. Method: Twenty-four children aged 5 to 7 years old participated in this case-control study,…

  18. Regenerating titanium ventricular assist device surfaces after gold/palladium coating for scanning electron microscopy.

    Science.gov (United States)

    Achneck, Hardean E; Serpe, Michael J; Jamiolkowski, Ryan M; Eibest, Leslie M; Craig, Stephen L; Lawson, Jeffrey H

    2010-01-01

    Titanium is one of the most commonly used materials for implantable devices in humans. Scanning electron microscopy (SEM) serves as an important tool for imaging titanium surfaces and analyzing cells and other organic matter adhering to titanium implants. However, high-vacuum SEM imaging of a nonconductive sample requires a conductive coating on the surface. A gold/palladium coating is commonly used and to date no method has been described to "clean" such gold/palladium covered surfaces for repeated experiments without etching the titanium itself. This constitutes a major problem with titanium-based implantable devices which are very expensive and thus in short supply. Our objective was to devise a protocol to regenerate titaniumsurfaces after SEM analysis. In a series of experiments, titanium samples from implantable cardiac assist devices were coated with fibronectin, seeded with cells and then coated with gold/palladium for SEM analysis. X-ray photoelectron spectroscopy spectra were obtained before and after five different cleaning protocols. Treatment with aqua regia (a 1:3 solution of concentrated nitric and hydrochloric acid), with or without ozonolysis, followed by sonication in soap solution and sonication in deionized water, allowed regenerating titanium surfaces to their original state. Atomic force microscopy confirmed that the established protocol did not alter the titanium microstructure. The protocol described herein is applicable to almost all titanium surfaces used in biomedical sciences and because of its short exposure time to aqua regia, will likely work for many titanium alloys as well. (c) 2009 Wiley-Liss, Inc.

  19. Measurement of the product attitudes of youth during the selection of assistive technology devices.

    Science.gov (United States)

    Ryan, Stephen E; Klejman, Susan; Gibson, Barbara E

    2013-01-01

    This article proposes a conceptual underpinning for and examines the validity of the Youth Evaluation of Products (YEP) scale when used to measure the AT device attitudes of youth. Consumer socialization is promoted to improve the utility of an AT device selection framework for children and youth and inform the development of the YEP scale. A descriptive, qualitative mixed-methods design explored the validity of the scale when used by six manual wheelchair users, aged 11-14 years, to evaluate a new pushrim-activated, power-assisted wheelchair. Three youth participated in a subsequent focus group to share how they assessed wheelchair products. The items and dimensions of the YEP scale corresponded well to participants' views about wheelchairs. Consumer socialization provides a new way to understand the developing role of youth as AT consumers and the YEP scale is emerging as a way to measure their product attitudes. When integrated with contemporary thinking about the assessment and selection of AT devices, providers and parents may be better able to incorporate the product perspectives of youth during this shared decision-making process. [Box: see text].

  20. Quality of life and functional capacity outcomes in the MOMENTUM 3 trial at 6 months: A call for new metrics for left ventricular assist device patients.

    Science.gov (United States)

    Cowger, Jennifer A; Naka, Yoshifumi; Aaronson, Keith D; Horstmanshof, Douglas; Gulati, Sanjeev; Rinde-Hoffman, Debbie; Pinney, Sean; Adatya, Sirtaz; Farrar, David J; Jorde, Ulrich P

    2018-01-01

    The Multicenter Study of MAGLEV Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) clinical trial demonstrated improved 6-month event-free survival, but a detailed analysis of health-related quality of life (HR-QOL) and functional capacity (FC) was not presented. Further, the effect of early serious adverse events (SAEs) on these metrics and on the general ability to live well while supported with a left ventricular assist system (LVAS) warrants evaluation. FC (New York Heart Association [NYHA] and 6-minute walk test [6MWT]) and HR-QOL (European Quality of Life [EQ-5D-5L] and the Kansas City Cardiomyopathy [KCCQ]) assessments were obtained at baseline and 6 months after HeartMate 3 (HM3, n = 151; Abbott, Abbott Park, IL) or HeartMate II (HMII, n = 138; Abbott) implant as part of the MOMENTUM 3 clinical trial. Metrics were compared between devices and in those with and without events. The proportion of patients "living well on an LVAS" at 6 months, defined as alive with satisfactory FC (NYHA I/II or 6MWT > 300 meters) and HR-QOL (overall KCCQ > 50), was evaluated. Although the median (25th-75th percentile) patient KCCQ (change for HM3: +28 [10-46]; HMII: +29 [9-48]) and EQ-5D-5L (change for HM3: -1 [-5 to 0]; HMII: -2 [-6 to 0]) scores improved from baseline to 6 months (p 0.05). Likewise, there was an equivalent improvement in 6MWT distance at 6 months in HM3 (+94 [1-274] meters] and HMII (+188[43-340 meters]) from baseline. In patients with SAEs (n = 188), 6MWTs increased from baseline (p metrics did not change. The development of left ventricular assist device-specific HR-QOL tools is needed to better characterize the effect of SAEs on a patient's well-being. MOMENTUM 3 clinical trial #NCT02224755. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  1. Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Q; Snyder, J; Wang, C; Guceri, S; Sun, W [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Timmer, M; Hammer, J, E-mail: sunwei@drexel.edu [Advanced Technologies and Regenerative Medicine, Somerville, NJ (United States)

    2011-09-15

    In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 deg. C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 deg. C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

  2. Advantages and disadvantages of using intravenous tissue Plasminogen activator as salvage therapy for inoperable HeartWare thrombosis.

    Science.gov (United States)

    Basken, Robyn; Bazzell, Charles M; Smith, Richard; Janardhanan, Rajesh; Khalpey, Zain

    2017-07-01

    Device thrombosis is a devastating complication of left ventricular assist devices. The definitive treatment has been device exchange or explant. Evidence of increasing morbidity and mortality with device exchange has shifted strategies toward conservative management. In this report, we detail the use of thrombolytics as salvage therapy in a patient with an occlusive HeartWare ventricular assist device (HeartWare Inc., Framingham, MA) thrombus, resulting in long-term survival without further intervention. © 2017 Wiley Periodicals, Inc.

  3. A MOBILE-DEVICE-SUPPORTED PEER-ASSISTED LEARNING SYSTEM FOR COLLABORATIVE EARLY EFL READING

    Directory of Open Access Journals (Sweden)

    Yu-Ju Lan

    2007-02-01

    Full Text Available Collaborative learning methods which emphasize peer interaction have been widely applied to increase the intensity and effectiveness of EFL reading programs. However, simply grouping students heterogeneously and assigning them group goals does not guarantee that effective collaborative learning will ensue. The present research includes two studies. In Study One, the weaknesses of collaborative learning in a traditional EFL setting were observed. Then, in Study Two, a mobile-device-supported peer-assisted learning (MPAL system was developed for the purpose of addressing the identified weaknesses. Two classes of twenty-six third grade students participated in the present research to examine the unique contribution of MPAL to collaborative EFL reading activities. The collaborative behavior of elementary EFL learners was videotaped and analyzed. Detailed analysis of the videotaped behavior indicated that MPAL helped improve collaboration in elementary school level EFL learners and promotes their reading motivation.

  4. Multifactorial assistive device intervention to prevent low back pain among caregivers

    DEFF Research Database (Denmark)

    Jensen, Stina Bjørnskov; Brandt, Åse

    2011-01-01

    strain during person transfer, self reported low back pain and low back injuries as main outcomes. The intervention was implemented in one municipality consisting of maximum use of assistive devices for person transfer combined with organizational changes. The other municipality served as control group....... The study population consisted of all permanently employed caregivers in the two municipalities, and data was collected by means of a questionnaire at baseline and after 10 months of follow-up. At follow-up the caregivers in the intervention group reported lower perceived strain during person transfer......Caregivers are among those professionals who experience the highest incidence of low back pain and low back injuries, and one of the most frequently described reasons for this is person transfers. This paper reports on a controlled intervention study in two Danish municipalities with perceived...

  5. Singularity now: using the ventricular assist device as a model for future human-robotic physiology.

    Science.gov (United States)

    Martin, Archer K

    2016-04-01

    In our 21 st century world, human-robotic interactions are far more complicated than Asimov predicted in 1942. The future of human-robotic interactions includes human-robotic machine hybrids with an integrated physiology, working together to achieve an enhanced level of baseline human physiological performance. This achievement can be described as a biological Singularity. I argue that this time of Singularity cannot be met by current biological technologies, and that human-robotic physiology must be integrated for the Singularity to occur. In order to conquer the challenges we face regarding human-robotic physiology, we first need to identify a working model in today's world. Once identified, this model can form the basis for the study, creation, expansion, and optimization of human-robotic hybrid physiology. In this paper, I present and defend the line of argument that currently this kind of model (proposed to be named "IshBot") can best be studied in ventricular assist devices - VAD.

  6. Using Technology in Social Work Practice: The mDad (Mobile Device Assisted Dad Case Study

    Directory of Open Access Journals (Sweden)

    Shawna J. Lee

    2015-07-01

    Full Text Available Mobile technology presents an exciting opportunity for social workers to reach populations that are typically underserved by interventions and services. We present one application of technology that is particularly relevant to social work practice. The mDad (Mobile Device Assisted Dad app was developed to augment existing social work practices by providing a father-friendly tool to help new fathers learn about and engage with their infants and toddlers. We discuss the process of developing the app content and conducting usability testing of the mDad app. We conclude with a discussion of the lessons learned from the mDad project, and the challenges of implementation and dissemination of technology-based interventions in community contexts.

  7. Which Antiplatelet Therapy in Patients With Left Ventricular Assist Device and Aspirin Allergy?

    Science.gov (United States)

    Consolo, Filippo; Pozzi, Loris; Sferrazza, Giulia; Della Valle, Patrizia; D'Angelo, Armando; Slepian, Marvin J; Pappalardo, Federico

    2018-02-01

    In patients with left ventricular assist device support and aspirin allergy, the choice of effective antiplatelet strategy remains a challenge. We compared the antithrombotic effect of clopidogrel vs ticagrelor in an LVAD patient with aspirin allergy by using a modified protocol of the thrombin generation test, accounting selectively for the platelet contribution on thrombin generation. Our results demonstrate enhanced antithrombotic efficacy offered by ticagrelor. Consistent with experimental results, the patient has passed more than 300 days without thromboembolic complications. This study provides additional mechanistic rationale supporting clinical evidence and opens the perspective to identify individual poor responsiveness to drugs by specifically evaluating drug-mediated platelet function. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Genetic algorithm optimization of transcutaneous energy transmission systems for implantable ventricular assist devices.

    Science.gov (United States)

    Byron, Kelly; Bluvshtein, Vlad; Lucke, Lori

    2013-01-01

    Transcutaneous energy transmission systems (TETS) wirelessly transmit power through the skin. TETS is particularly desirable for ventricular assist devices (VAD), which currently require cables through the skin to power the implanted pump. Optimizing the inductive link of the TET system is a multi-parameter problem. Most current techniques to optimize the design simplify the problem by combining parameters leading to sub-optimal solutions. In this paper we present an optimization method using a genetic algorithm to handle a larger set of parameters, which leads to a more optimal design. Using this approach, we were able to increase efficiency while also reducing power variability in a prototype, compared to a traditional manual design method.

  9. Stability effects of singularities in force-controlled robotic assist devices

    Science.gov (United States)

    Luecke, Greg R.

    2002-02-01

    Force feedback is being used as an interface between humans and material handling equipment to provide an intuitive method to control large and bulky payloads. Powered actuation in the lift assist device compensates for the inertial characteristics of the manipulator and the payload to provide effortless control and handling of manufacturing parts, components, and assemblies. The use of these Intelligent Assist Devices (IAD) is being explored to prevent worker injury, enhance material handling performance, and increase productivity in the workplace. The IAD also provides the capability to shape and control motion in the workspace during routine operations. Virtual barriers can be developed to protect fixed objects in the workspace, and regions can be programmed that attract the work piece to a certain position and orientation. However, the robot is still under complete control of the human operator, with the trajectory being determined and commanded using the judgment of the operator to complete a given task. In many cases, the IAD is built in a configuration that may have singular points inside the workspace. These singularities can cause problems when the unstructured trajectory commands from the human cause interaction between the IAD and the virtual walls and fixtures at positions close to these singularities. The research presented here explores the stability effects of the interactions between the powered manipulator and the virtual surfaces when controlled by the operator. Because of the flexible nature of the human decisions determining the real time work piece paths, manipulator singularities that occur in conjunction with the virtual surfaces raise stability issues in the performance around these singularities. We examine these stability issues in the context of a particular IAD configuration, and present analytic results for the performance and stability of these systems in response to the real-time trajectory modification of the human operator.

  10. Usability and safety of ventricular assist devices: human factors and design aspects.

    Science.gov (United States)

    Geidl, Lorenz; Zrunek, Philipp; Deckert, Zeno; Zimpfer, Daniel; Sandner, Sigrid; Wieselthaler, Georg; Schima, Heinrich

    2009-09-01

    The purpose of this study was the investigation of the usability and ergonomics of ventricular assist devices (VADs) in everyday usage. Patients with four different VAD types were observed. After implantation, instruction, and discharge from the hospital, the patients returned on a regular basis to the outpatient clinic, where the investigation took place. Data collection took place in two phases. In phase I home-released VAD patients were asked about perceived problems with the system at home. Additionally health-care professionals were interviewed to gather information on frequent VAD inconveniences and shortcomings. This inquiry resulted in a standardized self-assessment questionnaire and a manual skill test, which were performed in phase II by the whole collective (16 patients and ongoing). As a result, 38% of the patients disconnected parts of their system unintentionally at least once. All of them ascribed this problem to their own carelessness. Thirty-eight percent had to replace a cable. Seventy-five percent desired an additional cable strain relief. Thirty-eight percent suffered from rubbing of parts on the body. Sixty-three percent used a separate repository aside from the factory-provided transportation systems. The overall noise emission (pump, ventilators, and alarms) annoyed 56%; however, for 32% the alarm signals were too quiet to wake them up. No correlation between the assessed manual skills and the number of adverse events was found. To conclude, this preliminary study revealed considerable potential for improvements in the usability of ventricular assist systems.

  11. A novel ventricular restraint device (ASD) repetitively deliver Salvia miltiorrhiza to epicardium have good curative effects in heart failure management.

    Science.gov (United States)

    Naveed, Muhammad; Wenhua, Li; Gang, Wang; Mohammad, Imran Shair; Abbas, Muhammad; Liao, Xiaoqian; Yang, Mengqi; Zhang, Li; Liu, Xiaolin; Qi, Xiaoming; Chen, Yineng; Jiadi, Lv; Ye, Linlan; Zhijie, Wang; Ding, Chen Ding; Feng, Yu; Xiaohui, Zhou

    2017-11-01

    A novel ventricular restraint is the non-transplant surgical option for the management of an end-stage dilated heart failure (HF). To expand the therapeutic techniques we design a novel ventricular restraint device (ASD) which has the ability to deliver a therapeutic drug directly to the heart. We deliver a Traditional Chinese Medicine (TCM) Salvia miltiorrhiza (Danshen Zhusheye) through active hydraulic ventricular support drug delivery system (ASD) and we hypothesize that it will show better results in HF management than the restraint device and drug alone. SD rats were selected and divided into five groups (n=6), Normal, HF, HF+SM (IV), HF+ASD, HF+ASD+SM groups respectively. Post myocardial infarction (MI), electrocardiography (ECG) showed abnormal heart function in all groups and HF+ASD+SM group showed a significant therapeutic improvement with respect to other treatment HF, HF+ASD, and HF+SM (IV) groups on day 30. The mechanical functions of the heart such as heart rate, LVEDP, and LVSP were brought to normal when treated with ASD+SM and show significant (P valueASD+SM group animals compared with other treatment groups. Masson's Trichrome staining was used to study histopathology of cardiac myocytes and quantification of fibrosis was assessed. The large blue fibrotic area was observed in HF, HF+ASD, and HF+SM (IV) groups while HF+ASD+SM showed negligible fibrotic myocyte at the end of study period (30days). This study proves that novel ASD device augments the therapeutic effect of the drug and delivers Salvia miltiorrhiza to the cardiomyocytes significantly as well as provides additional support to the dilated ventricle by the heart failure. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Handheld fetal Doppler device for assessing heart rate in neonatal resuscitation.

    Science.gov (United States)

    Shimabukuro, Rinshu; Takase, Kozo; Ohde, Sachiko; Kusakawa, Isao

    2017-10-01

    The use of neonatal three-lead electrocardiograms (Neo-ECG) is suggested for the assessment of heart rate (HR) in neonatal resuscitation, but primary childbirth facilities (i.e. maternity clinics or maternity homes) are not sufficiently equipped for this. The aim of this study was to therefore to confirm the potential of a handheld fetal Doppler device (FDD), widely used to assess HR in labor room resuscitation, and to compare its equivalency to Neo-ECG. In low-risk full-term infants, HR was measured five times per minute in minutes 1-5 after delivery using the FDD and Neo-ECG, and their equivalence compared. The equivalence margin was set at a HR difference of HR was displayed were measured for both methods. FDD and Neo-ECG HR correlated strongly (r = 0.977) in 155 measurements in 33 cases. The mean HR difference was -0.123 beats/min (95%CI: -0.594 to +0.345), and the logarithmic transformation of the HR ratio was -0.0003 (95%CI: -0.0020 to +0.0015). The mean HR difference and HR ratio were within the equivalence margin. For HR assessment using the FDD, 155 of 165 measurements (93.9%) could be obtained in HR assessment, FDD is a valid substitute for Neo-ECG in primary childbirth facilities that are not sufficiently equipped for Neo-ECG. © 2017 Japan Pediatric Society.

  13. Multi-Targeted Antithrombotic Therapy for Total Artificial Heart Device Patients.

    Science.gov (United States)

    Ramirez, Angeleah; Riley, Jeffrey B; Joyce, Lyle D

    2016-03-01

    To prevent thrombotic or bleeding events in patients receiving a total artificial heart (TAH), agents have been used to avoid adverse events. The purpose of this article is to outline the adoption and results of a multi-targeted antithrombotic clinical procedure guideline (CPG) for TAH patients. Based on literature review of TAH anticoagulation and multiple case series, a CPG was designed to prescribe the use of multiple pharmacological agents. Total blood loss, Thromboelastograph(®) (TEG), and platelet light-transmission aggregometry (LTA) measurements were conducted on 13 TAH patients during the first 2 weeks of support in our institution. Target values and actual medians for postimplant days 1, 3, 7, and 14 were calculated for kaolinheparinase TEG, kaolin TEG, LTA, and estimated blood loss. Protocol guidelines were followed and anticoagulation management reduced bleeding and prevented thrombus formation as well as thromboembolic events in TAH patients postimplantation. The patients in this study were susceptible to a variety of possible complications such as mechanical device issues, thrombotic events, infection, and bleeding. Among them all it was clear that patients were at most risk for bleeding, particularly on postoperative days 1 through 3. However, bleeding was reduced into postoperative days 3 and 7, indicating that acceptable hemostasis was achieved with the anticoagulation protocol. The multidisciplinary, multi-targeted anticoagulation clinical procedure guideline was successful to maintain adequate antithrombotic therapy for TAH patients.

  14. Satisfaction with assistive technology device in relation to the service delivery process-A systematic review.

    Science.gov (United States)

    Larsson Ranada, Åsa; Lidström, Helene

    2017-09-11

    The service delivery process (SDP) of assistive technology devices (ATDs) is attracting interest, as the provision of ATDs is critical for the independence and participation in society of individuals with disabilities. The purpose of the current study was to investigate what impact the SDP has on satisfaction with ATDs in individuals with disabilities in relation to everyday activities. A systematic literature review was conducted, which resulted in 53 articles included. The results showed that there are factors in almost all the different steps of the SDP that affect the satisfaction with of the devices, which can lead to underutilization and abandonment of ATDs. Only a few studies have been conducted with a design robust enough to generalize the results; therefore, more research is needed. Therefore, the conclusion is the SDP as a whole contributes to the satisfaction with and usability of ATDs in individuals with disability in relation to achieving the desired goals of participation in everyday activities, for the articles included must be deemed as moderate. A client-centred approach in the process is advocated, and was found to be an important factor for an effective SDP and satisfied users.

  15. The influence of assistive technology devices on the performance of activities by visually impaired

    Directory of Open Access Journals (Sweden)

    Suzana Rabello

    2014-04-01

    Full Text Available Objective: To establish the influence of assistive technology devices (ATDs on the performance of activities by visually impaired schoolchildren in the resource room. Methods: A qualitative study that comprised observation and an educational intervention in the resource room. The study population comprised six visually impaired schoolchildren aged 12 to 14 years old. The participants were subjected to an eye examination, prescribed ATDs comprising optical and non-optical devices, and provided an orientation on the use of computers. The participants were assessed based on eye/object distance, font size, and time to read a computer screen and printed text. Results: The ophthalmological conditions included corneal opacity, retinochoroiditis, retinopathy of prematurity, aniridia, and congenital cataracts. Far visual acuity varied from 20/200 to 20/800 and near visual acuity from 0.8 to 6 M. Telescopes, spherical lenses, and support magnifying glasses were prescribed. Three out of five participants with low vision after intervention could decrease the font size on the screen computer, and most participants (83.3% reduced their reading time at the second observation session. Relative to the printed text, all the participants with low vision were able to read text written in smaller font sizes and reduced their reading time at the second observation session. Conclusion: Reading skills improved after the use of ATDs, which allowed the participants to perform their school tasks equally to their classmates.

  16. The personal lift-assist device and lifting technique: a principal component analysis.

    Science.gov (United States)

    Sadler, Erin M; Graham, Ryan B; Stevenson, Joan M

    2011-04-01

    The personal lift-assist device (PLAD) is a non-motorised, on-body device that acts as an external force generator using the concept of stored elastic energy. In this study, the effect of the PLAD on the lifting kinematics of male and female lifters was investigated using principal component analysis. Joint kinematic data of 15 males and 15 females were collected using an opto-electronic system during a freestyle, symmetrical-lifting protocol with and without wearing the PLAD. Of the 31 Principal Components (PCs) retained in the models, eight scores were significantly different between the PLAD and no-PLAD conditions. There were no main effects for gender and no significant interactions. Results indicated that the PLAD similarly affected the lifting kinematics of males and females; demonstrating significantly less lumbar and thoracic flexion and significantly greater hip and ankle flexion when wearing the PLAD. These findings add to the body of work that suggest the PLAD may be a safe and effective ergonomic aid. STATEMENT OF RELEVANCE: The PLAD is an ergonomic aid that has been shown to be effective at reducing low back demands during manual materials handling tasks. This body of work establishes that the PLAD encourages safe lifting practices without adversely affecting lifting technique.

  17. HIV viral RNA extraction in wax immiscible filtration assisted by surface tension (IFAST) devices.

    Science.gov (United States)

    Berry, Scott M; LaVanway, Alex J; Pezzi, Hannah M; Guckenberger, David J; Anderson, Meghan A; Loeb, Jennifer M; Beebe, David J

    2014-05-01

    The monitoring of viral load is critical for proper management of antiretroviral therapy for HIV-positive patients. Unfortunately, in the developing world, significant economic and geographical barriers exist, limiting access to this test. The complexity of current viral load assays makes them expensive and their access limited to advanced facilities. We attempted to address these limitations by replacing conventional RNA extraction, one of the essential processes in viral load quantitation, with a simplified technique known as immiscible filtration assisted by surface tension (IFAST). Furthermore, these devices were produced via the embossing of wax, enabling local populations to produce and dispose of their own devices with minimal training or infrastructure, potentially reducing the total assay cost. In addition, IFAST can be used to reduce cold chain dependence during transportation. Viral RNA extracted from raw samples stored at 37°C for 1 week exhibited nearly complete degradation. However, IFAST-purified RNA could be stored at 37°C for 1 week without significant loss. These data suggest that RNA isolated at the point of care (eg, in a rural clinic) via IFAST could be shipped to a central laboratory for quantitative RT-PCR without a cold chain. Using this technology, we have demonstrated accurate and repeatable measurements of viral load on samples with as low as 50 copies per milliliter of sample. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  18. Electrospray-assisted characterization and deposition of chlorosomes to fabricate a biomimetic light-harvesting device

    Energy Technology Data Exchange (ETDEWEB)

    Modesto-Lopez, Luis B.; Thimsen, Elijah J.; Collins, Aaron M.; Blankenship, R. E.; Biswas, Pratim

    2010-01-01

    Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic bacteria such as Chloroflexus aurantiacus have supramolecular antenna complexes called chlorosomes attached to their cytoplasmic membrane that increase the cross section for light absorption even in low-light conditions. Self-assembled bacteriochlorophyll pigments in the chlorosome interior play a key role in the efficient transfer and funneling of the harvested energy. In this work it was demonstrated that chlorosomes can be rapidly and precisely size-characterized online in real time using an electrospray-assisted mobility-based technique. Chlorosomes were electrospray-deposited onto TiO{sub 2} nanostructured films with columnar morphology to fabricate a novel biomimetic device to overcome the solvent compatibility issues associated with biological particles and synthetic dyes. The assembled unit retained the viability of the chlorosomes, and the harvesting of sunlight over a broader range of wavelengths was demonstrated. It was shown that the presence of chlorosomes in the biomimetic device had a 30-fold increase in photocurrent.

  19. A study on ship automatic berthing with assistance of auxiliary devices

    Directory of Open Access Journals (Sweden)

    Van Luong Tran

    2012-09-01

    Full Text Available The recent researches on the automatic berthing control problems have used various kinds of tools as a control method such as expert system, fuzzy logic controllers and artificial neural network (ANN. Among them, ANN has proved to be one of the most effective and attractive options. In a marine context, the berthing maneuver is a complicated procedure in which both human experience and intensive control operations are involved. Nowadays, in most cases of berthing operation, auxiliary devices are used to make the schedule safer and faster but none of above researches has taken into account. In this study, ANN is applied to design the controllers for automatic ship berthing using assistant devices such as bow thruster and tug. Using back-propagation algorithm, we trained ANN with set of teaching data to get a minimal error between output values and desired values of four control outputs including rudder, propeller revolution, bow thruster and tug. Then, computer simulations of automatic berthing were carried out to verify the effecttiveness of the system. The results of the simulations showed good performance for the proposed berthing control system.

  20. A practical review for cardiac rehabilitation professionals of continuous-flow left ventricular assist devices: historical and current perspectives.

    Science.gov (United States)

    Compostella, Leonida; Russo, Nicola; Setzu, Tiziana; Bottio, Tomaso; Compostella, Caterina; Tarzia, Vincenzo; Livi, Ugolino; Gerosa, Gino; Iliceto, Sabino; Bellotto, Fabio

    2015-01-01

    An increasing number of patients with end-stage heart failure are being treated with continuous-flow left ventricular assist devices (cf-LVADs). These patients provide new challenges to the staff in exercise-based cardiac rehabilitation (CR) programs. Even though experience remains limited, it seems that patients supported by cf-LVADs may safely engage in typical rehabilitative activities, provided that some attention is paid to specific aspects, such as the presence of a short external drive line. In spite of initial physical deconditioning, CR allows progressive improvement of symptoms such as fatigue and dyspnea. Intensity of rehabilitative activities should ideally be based on measured aerobic capacity and increased appropriately over time. Regular, long-term exercise training results in improved physical fitness and survival rates. Appropriate adjustment of cf-LVAD settings, together with maintenance of adequate blood volume, provides maximal output, while avoiding suction effects. Ventricular arrhythmias, although not necessarily constituting an immediate life-threatening situation, deserve treatment as they could lead to an increased rate of hospitalization and poorer quality of life. Atrial fibrillation may worsen symptoms of right ventricular failure and reduce exercise tolerance. Blood pressure measurements are possible in cf-LVAD patients only using a Doppler technique, and a mean blood pressure ≤80 mmHg is considered "ideal." Some patients may present with orthostatic intolerance, related to autonomic dysfunction. While exercise training constitutes the basic rehabilitative tool, a comprehensive intervention that includes psychological and social support could better meet the complex needs of patients in which cf-LVAD may offer prolonged survival.

  1. Family caregivers' inside perspectives: caring for an adult with a left ventricular assist device as a destination therapy.

    Science.gov (United States)

    Marcuccilli, Linda; Casida, Jesus Jessie; Bakas, Tamilynn; Pagani, Francis D

    2014-12-01

    Understanding the experience of caring for an adult with a left-ventricular assist device as a destination therapy (LVAD-DT) remains in its infancy. A hermeneutic-phenomenological inquiry guided by van Manen's methods was used to explore the LVAD-DT family caregiving experience.Participants/Setting-Seven family caregivers (1 man and 6 women) 50 to 74 years old who cared for an adult with an LVAD-DT in home settings. Recruitment and data collection occurred in an outpatient mechanical circulatory support center in the Midwest. Data were collected by means of face-to-face interviews using open-ended questions and 1 follow-up interview. Interviews were audio recorded and transcribed verbatim. Thematic analysis consisted of writing, rewriting, and reflecting across participants' data, which produced themes illustrating the experience and meaning of caring for an adult with an LVAD-DT. Themes were consensually validated. Procedures for trustworthiness are described. Five main themes were identified from participants' experiences: (1) advanced heart failure is a life-changing event, (2) self-doubt about LVAD caregiving improves over time, (3) lifestyle adjustments come with time, (4) persistent worry and stress, and (5) caregiving is not a burden-it's a part of life. These main themes were elucidated by 8 subthemes in which participants described a process of adjustment despite persistent worry and stress and eventually accepted caregiving as part of their lives. Future studies are needed to explore caregiver burden, adaptation, and the effects of caregiving outcomes, such as emotional and physical health and overall quality of life.

  2. Therapeutic effect of a new warm moist air device assisted with eyelid massage on office dry eye

    Directory of Open Access Journals (Sweden)

    Bing Zhao

    2017-08-01

    Full Text Available AIM: To investigate the therapeutic effect of a new warm moist air device assisted with eyelid massage in the treatment of office dry eye(ODE.METHODS: Sixty ODE patients were recruited, and these patients were randomly divided into two groups. One group received artificial tear treatment, and the other group received a new eyelid warm moist air device combined with eyelid massage treatment. Subjects completed the ocular surface disease index(OSDI, which was followed by fluorescein tear breakup time(BUT, corneal fluorescein staining(CFS, Schirmer I test(SⅠtand meibomian gland secretion function evaluation at baseline, and 2 and 4wk after treatment.RESULTS: In these 60 patients, 48 patients(23 in artificial tear treated group and 25 in the new warm moist air device assisted with eyelid massage treated groupwere positive for meibomian gland dysfunction(MGD. Compared to artificial tear treatment, the new warm moist air device assisted with eyelid massage treatment showed favorable therapeutic effect on OSDI(FGroup=41.63, PFGroup=60.47,PFGroup=12.12,PFGroup=0.17, P>0.05, CFS(FGroup=1.79, P>0.05and meibomian gland expressibility(FGroup=0.68, P>0.05between the two groups during 4wk treatment. CONCLUSION: This new eyelid warm moist air device assisted with eyelid massage has favorable therapeutic effect over artificial tear in ODE treatment.

  3. A Review of Assistive Listening Device and Digital Wireless Technology for Hearing Instruments

    Science.gov (United States)

    Kim, Chun Hyeok

    2014-01-01

    Assistive listening devices (ALDs) refer to various types of amplification equipment designed to improve the communication of individuals with hard of hearing to enhance the accessibility to speech signal when individual hearing instruments are not sufficient. There are many types of ALDs to overcome a triangle of speech to noise ratio (SNR) problems, noise, distance, and reverberation. ALDs vary in their internal electronic mechanisms ranging from simple hard-wire microphone-amplifier units to more sophisticated broadcasting systems. They usually use microphones to capture an audio source and broadcast it wirelessly over a frequency modulation (FM), infra-red, induction loop, or other transmission techniques. The seven types of ALDs are introduced including hardwire devices, FM sound system, infra-red sound system, induction loop system, telephone listening devices, television, and alert/alarm system. Further development of digital wireless technology in hearing instruments will make possible direct communication with ALDs without any accessories in the near future. There are two technology solutions for digital wireless hearing instruments improving SNR and convenience. One is near-field magnetic induction combined with Bluetooth radio frequency (RF) transmission or proprietary RF transmission and the other is proprietary RF transmission alone. Recently launched digital wireless hearing aid applying this new technology can communicate from the hearing instrument to personal computer, phones, Wi-Fi, alert systems, and ALDs via iPhone, iPad, and iPod. However, it comes with its own iOS application offering a range of features but there is no option for Android users as of this moment. PMID:25566400

  4. A review of assistive listening device and digital wireless technology for hearing instruments.

    Science.gov (United States)

    Kim, Jin Sook; Kim, Chun Hyeok

    2014-12-01

    Assistive listening devices (ALDs) refer to various types of amplification equipment designed to improve the communication of individuals with hard of hearing to enhance the accessibility to speech signal when individual hearing instruments are not sufficient. There are many types of ALDs to overcome a triangle of speech to noise ratio (SNR) problems, noise, distance, and reverberation. ALDs vary in their internal electronic mechanisms ranging from simple hard-wire microphone-amplifier units to more sophisticated broadcasting systems. They usually use microphones to capture an audio source and broadcast it wirelessly over a frequency modulation (FM), infra-red, induction loop, or other transmission techniques. The seven types of ALDs are introduced including hardwire devices, FM sound system, infra-red sound system, induction loop system, telephone listening devices, television, and alert/alarm system. Further development of digital wireless technology in hearing instruments will make possible direct communication with ALDs without any accessories in the near future. There are two technology solutions for digital wireless hearing instruments improving SNR and convenience. One is near-field magnetic induction combined with Bluetooth radio frequency (RF) transmission or proprietary RF transmission and the other is proprietary RF transmission alone. Recently launched digital wireless hearing aid applying this new technology can communicate from the hearing instrument to personal computer, phones, Wi-Fi, alert systems, and ALDs via iPhone, iPad, and iPod. However, it comes with its own iOS application offering a range of features but there is no option for Android users as of this moment.

  5. Impeller-pump model derived from conservation laws applied to the simulation of the cardiovascular system coupled to heart-assist pumps.

    Science.gov (United States)

    Shi, Yubing; Korakianitis, Theodosios

    2018-02-01

    Previous numerical models of impeller pumps for ventricular assist devices utilize curve-fitted polynomials to simulate experimentally-obtained pressure difference versus flow rate characteristics of the pumps, with pump rotational speed as a parameter. In this paper the numerical model for the pump pressure difference versus flow rate characteristics is obtained by analytic derivation. The mass, energy and angular momentum conservation laws are applied to the working fluid passing through the impeller geometry and coupled with the turbomachine's velocity diagram. This results in the construction of a pressure difference versus flow rate characteristic for the specific pump geometry, with pump rotational speed as parameter. Overall this model allows modifications of the pump geometry, so that the pump avoids undesirable operating conditions, such as regurgitant flow. The HeartMate III centrifugal pump is used as an example to demonstrate the application of the technique. The parameterised numerical model for HeartMate III derived by this technique is coupled with a numerical model for the human cardiovascular system, and the combination is used to investigate the cardiovascular response under different conditions of impeller pump support. Conditions resulting in regurgitant pump flow, the pump resulting in aortic valve closure and taking over completely the pumping action from the diseased heart, and inner ventricular wall suction at pump inlet are predicted by the model. The simulation results suggest that for normal HeartMate III operation the pump speed should be maintained between 3,100 and 4,500 rpm to avoid regurgitant pump flow and ventricular suction. To obtain optimal overall cardiovascular system plus pump response, the pump operating speed should be 3,800 rpm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Percutaneous implantation of a ventricular partitioning device for treatment of ischemic heart failure: initial experience of a center.

    Science.gov (United States)

    Silva, Guida; Melica, Bruno; Pires de Morais, Gustavo; Sousa, Olga; Bettencourt, Nuno; Ribeiro, José; Simões, Lino; Gama, Vasco

    2012-12-01

    The Parachute is a novel left ventricular (LV) partitioning device that is deployed percutaneously in the left ventricle in patients with anteroapical regional wall motion abnormalities, dilated LV and systolic dysfunction after anterior myocardial infarction (MI). The implantable device is a partitioning membrane that isolates the dysfunctional region of the ventricle and decreases chamber volume. Data from the first-in-human clinical trial - the Percutaneous Ventricular Restoration in Chronic Heart Failure (PARACHUTE) trial- has shown that this new device is associated with significant and sustained LV volume reduction and improvement in LV hemodynamics and functional capacity in the 12 months after implantation, with a relatively low rate of clinical events, indicating that it may have a beneficial effect in the treatment of ischemic heart failure. We aim to describe our initial experience with implantation of the Parachute LV partitioning device and its short-term safety, defined as the successful delivery and deployment of the device. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  7. The provision of assistive devices and home adaptations to patients with ALS in the Netherlands: patients' perspectives

    NARCIS (Netherlands)

    Creemers, Huub; Beelen, Anita; Grupstra, Hepke; Nollet, Frans; van den Berg, Leonard H.

    2014-01-01

    The timely provision of assistive devices and home adaptations (ADHA) is crucial in the management of patients with amyotrophic lateral sclerosis (ALS) in order to maintain their independence and relieve their caregivers. Our objective was to study the experiences of patients with ALS during the

  8. Photo-assisted water splitting with bipolar membrane induced pH gradients for practical solar fuel devices

    NARCIS (Netherlands)

    Vermaas, D.A.; Sassenburg, M.; Smith, W.A.

    2015-01-01

    Different pH requirements for a cathode and an anode result in a non-optimal performance for practical solar fuel systems. We present for the first time a photo-assisted water splitting device using a bipolar membrane, which allows a cathode to operate in an acidic electrolyte while the photoanode

  9. Stroke rehabilitation: assistive technology devices and environmental modifications following primary rehabilitation in hospital--a therapeutic perspective

    DEFF Research Database (Denmark)

    Sørensen, Hanne Vinkel; Lendal, Susie; Schultz-Larsen, Kirsten

    2003-01-01

    home from three hospitals in Copenhagen from 1996 through 1998, constituted 20% of the total population of stroke survivors in this area. The results showed that 75% of these patients were provided with assistive devices and/or environmental modifications at discharge. Six months after discharge...

  10. Right ventricular dysfunction in children supported with pulsatile ventricular assist devices.

    Science.gov (United States)

    Karimova, Ann; Pockett, Charissa R; Lasuen, Nagore; Dedieu, Nathalie; Rutledge, Jennifer; Fenton, Mathew; Vanderpluym, Christina; Rebeyka, Ivan M; Dominguez, Troy E; Buchholz, Holger

    2014-05-01

    To describe the incidence and severity of right ventricular dysfunction (RVD) in pediatric ventricular assist device (VAD) recipients and to identify the preoperative characteristics associated with RVD and their effect on outcomes. Children bridged to transplantation from 2004 to 2011 were included. RVD was defined as the use of a left VAD (LVAD) with an elevated central venous pressure of >16 mm Hg with inotropic therapy and/or inhaled nitric oxide for >96 hours or biventricular assist (BiVAD). A total of 57 children (median age, 2.97 years; range 35 days to 15.8 years) were supported. Of the 57, 43 (75%) had an LVAD, and of those, 10 developed RVD. The remaining 14 (25%) required BiVAD. Thus, RVD occurred in 24 of 57 patients (42%). Preoperative variables such as younger age (P = .01), use of extracorporeal mechanical support (P = .006), and elevated urea (P = .03), creatinine (P = .02), and bilirubin (P = .001) were associated with RVD. Multiple logistic regression analysis indicated that elevated urea and extracorporeal mechanical support (odds ratio, 26.4; 95% confidence interval, 2.3-307.3; and odds ratio, 27.8; 95% confidence interval, 2.5-312.3, respectively) were risk factors for BiVAD. The patients who developed RVD on LVAD had a complicated postoperative course but excellent survival (100%), comparable to those with preserved right ventricular function (91%). The survival for those requiring BiVAD was reduced (71%). RVD occurred in approximately 40% of pediatric VAD recipients and affects their peri-implantation morbidity and bridging outcomes. Preoperative extracorporeal membrane oxygenation and elevated urea were risk factors for BiVAD. Additional studies of the management of RVD in children after VAD implantation are warranted. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  11. Current practices in the monitoring of cardiac rhythm devices in pediatrics and congenital heart disease.

    Science.gov (United States)

    Boyer, Stacey L; Silka, Michael J; Bar-Cohen, Yaniv

    2015-04-01

    Although guidelines for routine follow-up of pacemakers and implantable cardioverter defibrillators (ICDs) are available for adults, minimal data supports their appropriateness in pediatrics and congenital heart disease. This study aimed to define current practices of cardiac rhythm device (CRD) follow-up among pediatric electrophysiologists. Pediatric and Congenital EP Society (PACES) members were surveyed regarding frequency of CRD in-person follow-up as well as transtelephonic monitoring (TTM) and remote monitoring (RM) practices. If home monitoring was used, the effect on in-person follow-up was also evaluated. A total of 106 PACES members responded to the survey. Uncomplicated pacemaker and ICD patients were both followed in-person at a median interval of 6 months (range 1-12 months). TTM was utilized by 67 % of responders (median interval 3 months; range 1-6 months), while RM was used by 87 % for pacemakers (median interval 3 months; range 1-6 months) and 92 % for ICDs (median interval 3 months; range 2 weeks-6 months). When TTM was used, 21 % of responders reduced their frequency of pacemaker clinic visits. In comparison, RM reduced the frequency of clinic visits for pacemakers and ICDs in 32 and 31 % of responders, respectively. Patient age was an independent factor in determining CRD follow-up for 49 % of responders. While CRD follow-up by pediatric electrophysiologists in general follows adult guidelines, individual practices widely vary. In contrast to published recommendations in adults, TTM and RM utilization does not reduce the frequency of in-person visits for the majority of pediatric electrophysiologists.

  12. Percutaneous Mechanical Circulatory Support Using Impella® Devices for Decompensated Cardiogenic Shock: A Pediatric Heart Center Experience.

    Science.gov (United States)

    Parekh, Dhaval; Jeewa, Aamir; Tume, Sebastian C; Dreyer, William J; Pignatelli, Ricardo; Horne, David; Justino, Henri; Qureshi, Athar M

    2017-04-06

    Cardiogenic shock remains a significant cause of mortality and morbidity in children with heart failure. Percutaneous mechanical circulatory support may be an additional tool to augment left heart support and decompression in addition to conventional therapies. This report aims to review the clinical and hemodynamic outcomes of the Impella® device at a pediatric center. A retrospective review of all implants between October 2014 and November 2016 was conducted. Clinical outcomes, device implant techniques, complications, and hemodynamic data were collected. Statistical analysis was performed on hemodynamic and echocardiographic data. There were 10 Impella® device placements in 8 patients with a median age of 17 years (6.5 - 25) and support duration of 8 days (1-21). Implant diagnosis included 5 patients with either post-transplant rejection or allograft vasculopathy, 2 with myocarditis, and one patient with refractory ventricular tachycardia. ECMO support was required in 4 patients. Significant reduction in pulmonary capillary wedge pressures (ppediatric centers as a mode to augment cardiac output or to decompress the left heart in patients on ECMO or with cardiogenic shock.

  13. Outcomes of a Pharmacist-Managed Heart Failure Medication Titration Assistance Clinic.

    Science.gov (United States)

    Bhat, Shubha; Kansal, Mayank; Kondos, George T; Groo, Vicki

    2018-02-01

    National guidelines recommend angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs) and β-blockers (BBs) at target doses for morbidity and mortality benefits in heart failure with reduced ejection fraction (HFrEF); regardless, titration of these therapies in practice remains suboptimal. We implemented an outpatient pharmacist-managed HFrEF medication titration assistance clinic (MTAC) at one institution to improve titration for general cardiology (GC) patients. To evaluate MTAC impact by determining the proportion of patients on target or maximum tolerated ACE inhibitor/ARB and BB doses. A retrospective chart review of adult patients with documented ejection fraction ≤40% managed in the MTAC or GC from 2011 to 2013 was conducted. HFrEF medication regimens were collected at initial visit and months 1, 2, 3, 6, 9, and 12 to assess titration. Target doses were defined per guideline or dose at which ejection fraction recovered during the study. Maximum tolerated doses were defined as the highest dose patients tolerated without physiological limitations. Of 148 patients, the MTAC managed 51 and GC managed 97. At baseline, 90% of MTAC versus 82% of GC patients were prescribed ACE inhibitors/ARBs and BBs. In the MTAC, 4% were at target or maximum tolerated doses compared with 32% of GC patients ( P < 0.001). At 12 months, 95% of patients in the MTAC and 87% in GC were prescribed ACE inhibitors/ARBs and BBs. Of those prescribed ACE inhibitors/ARBs and BBs, 64% in the MTAC versus 40% in GC reached target or maximum tolerated doses ( P = 0.01). The pharmacist-managed MTAC increased the proportion of patients on optimal HFrEF therapies and are a resource for GC patients.

  14. Beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, nitrate-hydralazine, diuretics, aldosterone antagonist, ivabradine, devices and digoxin (BANDAID(2) ): an evidence-based mnemonic for the treatment of systolic heart failure.

    Science.gov (United States)

    Chia, N; Fulcher, J; Keech, A

    2016-06-01

    Heart failure causes significant morbidity and mortality, with recognised underutilisation rates of guideline-based therapies. Our aim was to review current evidence for heart failure treatments and derive a mnemonic summarising best practice, which might assist physicians in patient care. Treatments were identified for review from multinational society guidelines and recent randomised trials, with a primary aim of examining their effects in systolic heart failure patients on mortality, hospitalisation rates and symptoms. Secondary aims were to consider other clinical benefits. MEDLINE and EMBASE were searched using a structured keyword strategy and the retrieved articles were evaluated methodically to produce an optimised reference list for each treatment. We devised the mnemonic BANDAID (2) , standing for beta-blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, nitrate-hydralazine (or potentially neprilysin inhibitor), diuretics, aldosterone antagonist, ivabradine, devices (automatic implantable cardioverter defibrillator, cardiac resynchronisation therapy or both) and digoxin as a representation of treatments with strong evidence for their use in systolic heart failure. Treatment with omega-3 fatty acids, statins or anti-thrombotic therapies has limited benefits in a general heart failure population. Adoption of this mnemonic for current evidence-based treatments for heart failure may help improve prescribing rates and patient outcomes in this debilitating, high mortality condition. © 2016 Royal Australasian College of Physicians.

  15. Extracorporeal total artificial heart as bailout surgery.

    Science.gov (United States)

    Perrodin, Stéphanie F; Muller, Olivier; Gronchi, Fabrizio; Liaudet, Lucas; Hullin, Roger; Kirsch, Matthias

    2017-03-01

    We report the use of a total extracorporeal heart for uncontrolled bleeding following a proximal left anterior descending artery perforation, using two centrifugal ventricular assist devices after heart explantation. The literature describing similar techniques and patient outcomes for this "bailout" technique are reviewed. © 2017 Wiley Periodicals, Inc.

  16. Cardiac implantable electronic device remote monitoring surveillance in pediatric and congenital heart disease: Utility relative to frequency.

    Science.gov (United States)

    Dechert, Brynn E; Serwer, Gerald A; Bradley, David J; Dick, Macdonald; LaPage, Martin J

    2015-01-01

    Heart Rhythm Society expert consensus provides recommendations for surveillance monitoring of cardiac implantable electronic devices (CIEDs), but limited data are available for the pediatric and congenital heart disease population. The purpose of this study was to determine the rate of actionable events during CIED surveillance in this population, assess the utility of routine CIED remote monitoring, and assess the potential benefit from more frequent monitoring. This was a retrospective cohort study of all CIED patients followed at a pediatric and congenital heart center and enrolled in the Medtronic Carelink system with either (1) a chronic (implanted for >6 months) CIED followed between July 1, 2010, and July 1, 2012, on a bimonthly schedule; or (2) a new CIED (implanted pediatric and congenital heart disease patients, the rate of actionable events was low, especially on asymptomatic interrogations. Most actionable events were due to tachyarrhythmia. A more frequent than every 90-day monitoring schedule does not appear to be of significant benefit. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  17. Assistência circulatória com aparelho Heart Mate® na Cleveland Clinic Foundation: experiência inicial e futuras aplicações

    Directory of Open Access Journals (Sweden)

    Theófilo GAUZE

    1997-01-01

    Full Text Available Objetivo: Estudar a experiência inicial em assistência circulatória ventricular esquerda com o aparelho pneumático implantável Heart Mate® 1000 IP, analisando suas características e aplicações clínicas. Material e Métodos: Entre dez/91 e set/94 (45 meses 33 pacientes em choque cardiogênico por miocardiopatia isquêmica ou dilatada foram assistidos, com esse aparelho, por um tempo de 0 a 153 dias (média de 76 dias, nos pacientes que chegaram a ser transplantados. O diagnóstico, o tempo de assintência circulatória, os parâmetros hemodinâmicos (índice cardíaco, gradiente transpulmonar, fração de ejeção do ventrículo direito, resistência vascular pulmonar e variação da área do ventrículo direito, assim como as complicações clínicas são apresentados e discutidos. Valores pré e pós implante são apresentados como média +/- desvio padrão e comparados por teste T pareado. Resultados: A melhora hemodinâmica foi estatisticamente significante (pPurpose: To study and evaluate the current use of the Heart Mate® 1000 IP LVAD at the Cleveland Clinic Foundation. Methods: Between Dec/91 and Sept/94 the Heart Mate pneumatic LVAD was implanted in 33 severely shocked patients. Multiple hemodynamic measurements were done in the OR during implant, 24 hours later and just before the heart transplant. Numbers are presented in mean (+/- standard deviation and compared by paired T-test. Clinical outcome and complications are discussed. Results: Hemodynamic parameters markedly improved after device implantation (statistically significant. Support time ranged from 0 to 153 days (mean 76 in the group that reached the transplant. There were 9 (15% deaths due to right ventricular failure, sepsis and multiple organ failure. No thromboembolic events occurred. Conclusion: Treatment with the Heart Mate improved clinical outcome in high risk patients. The results encourage its application as a new alternative therapy to heart failure.

  18. A Novel Mean-Value Model of the Cardiovascular System Including a Left Ventricular Assist Device.

    Science.gov (United States)

    Ochsner, Gregor; Amacher, Raffael; Schmid Daners, Marianne

    2017-06-01

    Time-varying elastance models (TVEMs) are often used for simulation studies of the cardiovascular system with a left ventricular assist device (LVAD). Because these models are computationally expensive, they cannot be used for long-term simulation studies. In addition, their equilibria are periodic solutions, which prevent the extraction of a linear time-invariant model that could be used e.g. for the design of a physiological controller. In the current paper, we present a new type of model to overcome these problems: the mean-value model (MVM). The MVM captures the behavior of the cardiovascular system by representative mean values that do not change within the cardiac cycle. For this purpose, each time-varying element is manually converted to its mean-value counterpart. We compare the derived MVM to a similar TVEM in two simulation experiments. In both cases, the MVM is able to fully capture the inter-cycle dynamics of the TVEM. We hope that the new MVM will become a useful tool for researchers working on physiological control algorithms. This paper provides a plant model that enables for the first time the use of tools from classical control theory in the field of physiological LVAD control.

  19. Feasibility of Home-Use Animal-Assisted Activities in Patients With Implanted Cardiac Electronic Devices

    Directory of Open Access Journals (Sweden)

    Peter Jirak

    2016-02-01

    Full Text Available Animal-assisted activities (AAAs are mainly carried out in institutions. The aim of this prospective pilot study was to assess the willingness of patients with cardiac implanted electronic devices (IEDs to participate in AAA. The sample included 75 ambulatory patients (18 females, M age = 69 years, who attended an outpatient clinic for control of antibradycardic pacemakers (n = 15 or implanted cardioverter defibrillators (n = 60. Twenty-three percent were current and 48% were previous pet-owners. Current pet-owners were younger than non-pet-owners (63.5 vs. 72.0 years, p = .0003. Twelve patients (16% showed interest in AAA visits. However, only two patients agreed to an AAA visit. Both patients were visited once, but declined further visits. Hence, AAA sessions at home were poorly accepted, mainly because the patients considered themselves too busy or healthy, or due to a general disinterest in AAA. Potential health benefits associated with AAA may not be feasible to investigate during home visits of AAA-teams in patients with IEDs who are healthy enough to leave their homes. For further studies concerning AAA in patients with cardiovascular diseases, we suggest focusing on institutions like rehabilitation centers or day care centers and on more severely sick, homebound patients.

  20. Artificial placenta--lung assist devices for term and preterm newborns with respiratory failure.

    Science.gov (United States)

    Rochow, Niels; Chan, Emily C; Wu, Wen-I; Selvaganapathy, Ponnambalam R; Fusch, Gerhard; Berry, Leslie; Brash, John; Chan, Anthony K; Fusch, Christoph

    2013-06-25

    Respiratory insufficiency is a major cause of neonatal mortality and long-term morbidity, especially in very low birth weight infants. Today, non-invasive and mechanical ventilation are commonly accepted procedures to provide respiratory support to newborns, but they can reach their limit of efficacy. To overcome this technological plateau and further reduce mortality rates, the technology of an "artificial placenta", which is a pumpless lung assist device connected to the umbilical vessels, would serve to expand the therapeutic spectrum when mechanical ventilation becomes inadequate to treat neonates with severe respiratory insufficiency.
The first attempts to create such an artificial placenta took place more than 60 years ago. However, there has been a recent renaissance of this concept, including developments of its major components like the oxygenator, vascular access via umbilical vessels, flow control, as well as methods to achieve hemocompatibility in extracorporeal circuits. This paper gives a review of past and current development, animal experiments and human case studies of artificial placenta technology.

  1. Green Small Cell Operation of Ultra-Dense Networks Using Device Assistance

    Directory of Open Access Journals (Sweden)

    Gilsoo Lee

    2016-12-01

    Full Text Available As higher performance is demanded in 5G networks, energy consumption in wireless networks increases along with the advances of various technologies, so enhancing energy efficiency also becomes an important goal to implement 5G wireless networks. In this paper, we study the energy efficiency maximization problem focused on finding a suitable set of turned-on small cell access points (APs. Finding the suitable on/off states of APs is challenging since the APs can be deployed by users while centralized network planning is not always possible. Therefore, when APs in small cells are randomly deployed and thus redundant in many cases, a mechanism of dynamic AP turning-on/off is required. We propose a device-assisted framework that exploits feedback messages from the user equipment (UE. To solve the problem, we apply an optimization method using belief propagation (BP on a factor graph. Then, we propose a family of online algorithms inspired by BP, called DANCE, that requires low computational complexity. We perform numerical simulations, and the extensive simulations confirm that BP enhances energy efficiency significantly. Furthermore, simple, but practical DANCE exhibits close performance to BP and also better performance than other popular existing methods. Specifically, in a small-sized network, BP enhances energy efficiency 129%. Furthermore, in ultra-dense networks, DANCE algorithms successfully achieve orders of magnitude higher energy efficiency than that of the baseline.

  2. Germanium-Assisted Direct Growth of Graphene on Arbitrary Dielectric Substrates for Heating Devices.

    Science.gov (United States)

    Wang, Ziwen; Xue, Zhongying; Zhang, Miao; Wang, Yongqiang; Xie, Xiaoming; Chu, Paul K; Zhou, Peng; Di, Zengfeng; Wang, Xi

    2017-07-01

    Direct growth of graphene on dielectric substrates is a prerequisite to the development of graphene-based electronic and optoelectronic devices. However, the current graphene synthesis methods on dielectric substrates always involve a metal contamination problem, and the direct production of graphene patterns still remains unattainable and challenging. Herein, a semiconducting, germanium (Ge)-assisted, chemical vapor deposition approach is proposed to produce monolayer graphene directly on arbitrary dielectric substrates. By the prepatterning of a catalytic Ge layer, the graphene with desired pattern can be achieved conveniently and readily. Due to the catalysis of Ge, monolayer graphene is able to form on Ge-covered dielectric substrates including SiO2 /Si, quartz glass, and sapphire substrates. Optimization of the process parameters leads to complete sublimation of the catalytic Ge layer during or immediately after formation of the monolayer graphene, enabling direct deposition of large-area and continuous graphene on dielectric substrates. The large-area, highly conductive graphene synthesized on a transparent dielectric substrate using the proposed approach has exhibited a wide range of applications, including in both defogger and thermochromic displays, as already successfully demonstrated here. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Ventricular Energetics in Pediatric Left Ventricular Assist Device Patients: A Retrospective Clinical Study.

    Science.gov (United States)

    Di Molfetta, Arianna; Ferrari, Gianfranco; Iacobelli, Roberta; Filippelli, Sergio; Di Chiara, Luca; Guccione, Paolo; Amodeo, Antonio

    The aim of this study is to estimate the trend of right and left energetic parameters in left ventricular assist device (LVAD) pediatric patients. Echocardiographic data were retrospectively collected at the baseline, in the acute phase after and at the monthly follow-ups till the LVAD explantation to estimate left and right ventricular energetic parameters. A significant relationship between the left and right ventricular energetic parameter trends was found along all the study period. Left ventricular end-systolic pressure-volume relationship improved till the follow-up of 2 months and then progressively decreases. Left arteroventricular coupling decreases after the LVAD, and right arteroventricular coupling decreases at the short-term follow-up. Left ventricular external work, potential energy, and pressure-volume area decrease at the short-term follow-up and then increase progressively. Right ventricular external work, potential energy, and pressure-volume area increase after the LVAD implantation. Left (right) cardiac mechanical efficiency is improved (worsened) by the LVAD. Energetic variables show that the LVAD benefits could decrease over time. A continuous and patient tailored LVAD setting could contribute to prolong LVAD benefits. The introduction of energetic parameters could lead to a more complete evaluation of LVAD patients' outcome which is a multiparametric process.

  4. Reduction of driveline infections through doubled driveline tunneling of left ventricular assist devices.

    Science.gov (United States)

    Fleissner, Felix; Avsar, Murat; Malehsa, Doris; Strueber, Martin; Haverich, Axel; Schmitto, Jan D

    2013-01-01

    The durability of ventricular assist device (VAD) therapy improved steadily over the past years. However, driveline infections remain a challenge. To test whether an improved surgical implantation technique may lower the incidence of infections, we analyzed all patients receiving a VAD implantation in the years 2008 and 2009 (group 1) and compared them with all patients who received a VAD in 2011 (group 2) after we changed our implantation method. The new technique involves tunneling of the driveline into the fascia of the musculus rectus abdominis, resulting in a longer, intrafascial run to achieve a better resistance against ascending infections. We retrospectively analyzed 40 patients in group 1 and 41 patients in group 2. One year after implantation, the infection rate was markedly reduced (22.5% [n = 9] group 1 vs. 4.9% [n = 2] group 2, P great leap forward in long-term VAD treatment. However, overall mortality remains high and needs further improvement. © 2013, Copyright the Authors. Artificial Organs © 2013, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  5. Children at home on mechanical assistive devices and their families: a retrospective study.

    Science.gov (United States)

    Williams, P D; Williams, A R; Griggs, C

    1990-01-01

    Few assessments have been done of the influence of caregiver and family interactions on the developmental status of children discharged on mechanical assistive devices. The ages of the 25 children in this study ranged from 2-30 months. Seven were on apnea monitors at the time of the home interviews, and 18 had been off the monitors for 18 months or more. Mothers were administered six questionnaires: Family Adaptability and Cohesion Evaluation Scales (FACES III), Duke-UNC Functional Social Support Questionnaire, Families Coping Strategies (FCOPES), Self-Esteem Scale, Home Observation for Measurement of the Environment, and the Receptive-Expressive Emergent Language Scale (REEL). Results on the FACES III revealed that families were not rigid in adaptability; 61% were chaotic, and 33% were balanced. On the cohesion scale, 25% were disengaged, 30% were enmeshed, and 45% were balanced. On the FCOPES, and it's subscales, 36-40% of the respondents scored below the established norms. Social support was strongly correlated with Cohesion and Adaptability (r = .47, .67), HOME scores correlated with Self-Esteem (r = .47) and FCOPES Reframe scale (r = .45), and REEL scores correlated with Social Support (r = .47, .52). Path-analysis revealed two paths: help-seeking behaviors of the mother and the child-mother interactions.

  6. Hemodynamic effects of the vacuum-assisted closure device on open mediastinal wounds.

    Science.gov (United States)

    Conquest, Anne M; Garofalo, James H; Maziarz, David M; Mendelson, Kim G; Su Sun, You; Wooden, William A; Meadows, William M; Nifong, Wiley; Chitwood, W Randolph

    2003-12-01

    Application of the Vacuum-Assisted Closure device (VAC) to open sternal wounds has negative hemodynamic effects. We hypothesized that the interposition of a muscle flap attenuates these negative hemodynamic effects. After institutional approval, monitoring lines were placed in anesthetized, ventilated pigs. Through a median sternotomy, sonometric crystals were strategically positioned around the left ventricle. A rectus flap was rotated over the mediastinal wound, and the VAC was placed over the flap. After baseline measurements, a vacuum of 125 mmHg [Group (GP) 1, n = 5] or 50 mmHg (GP2, n = 6) was initiated. Hemodynamics were recorded every 15 min for 1.5 h, and 15 min after cessation of the vacuum therapy. GP3 (n = 6) underwent intermittent VAC cycling (on 5 min/off 2 min). Significance determined by t test. While non-flapped animals had significant detriment in both left ventricular filling volume and cardiac output, flapped animals had insignificant depression of both parameters. Application of muscle flaps to sternal wounds prior to VAC therapy significantly attenuates the negative hemodynamic effects seen when the VAC is used alone.

  7. Exercise in heart failure patients supported with a left ventricular assist device

    DEFF Research Database (Denmark)

    Jung, Mette Holme; Gustafsson, Finn

    2015-01-01

    determined by pump speed, the pressure difference across the pump, and in some cases ejection through the aortic valve. Fixed pump speed utilized in CF-LVADs may provide insufficient support, resulting in a moderate cardiac output increase during increased physical strain. Ongoing studies are evaluating...... factors are anemia with low oxygen-carrying capacity, obesity and general deconditioning with low muscle mass. In addition, exercise training in CF-LVAD patients can improve peak VO2. To design interventions to improve functional capacity in patients treated with modern durable LVADs, a detailed...

  8. The Role of Device Diagnostic Algorithms in the Assessment and Management of Patients with Systolic Heart Failure: A Review

    Directory of Open Access Journals (Sweden)

    Andrew C. T. Ha

    2011-01-01

    Full Text Available Hospitalization due to heart failure (HF exacerbation represents a major burden in health care and portends a poor long-term prognosis for patients. As a result, there is considerable interest to develop novel tools and strategies to better detect onset of volume overload, as HF hospitalizations may be reduced if appropriate interventions can be promptly delivered. One such innovation is the use of device-based diagnostic parameters in HF patients with implantable cardioverter defibrillators (ICD and/or cardiac resynchronization therapy (CRT devices. These diagnostic algorithms can effectively monitor and detect changes in patients' HF status, as well as predict one's risk of HF hospitalization. This paper will review the role of these device diagnostics parameters in the assessment and management of HF patients in ambulatory settings. In addition, the integration of these novel algorithms in existing HF disease management models will be discussed.

  9. Design and prototyping of a wristband-type wireless photoplethysmographic device for heart rate variability signal analysis.

    Science.gov (United States)

    Ghamari, M; Soltanpur, C; Cabrera, S; Romero, R; Martinek, R; Nazeran, H

    2016-08-01

    Heart Rate Variability (HRV) signal analysis provides a quantitative marker of the Autonomic Nervous System (ANS) function. A wristband-type wireless photoplethysmographic (PPG) device was custom-designed to collect and analyze the arterial pulse in the wrist. The proposed device is comprised of an optical sensor to monitor arterial pulse, a signal conditioning unit to filter and amplify the analog PPG signal, a microcontroller to digitize the analog PPG signal, and a Bluetooth module to transfer the data to a smart device. This paper proposes a novel model to represent the PPG signal as the summation of two Gaussian functions. The paper concludes with a verification procedure for HRV signal analysis during sedentary activities.

  10. Stereotypes Associated With Age-related Conditions and Assistive Device Use in Canadian Media.

    Science.gov (United States)

    Fraser, Sarah Anne; Kenyon, Virginia; Lagacé, Martine; Wittich, Walter; Southall, Kenneth Edmund

    2016-12-01

    Newspapers are an important source of information. The discourses within the media can influence public attitudes and support or discourage stereotypical portrayals of older individuals. This study critically examined discourses within a Canadian newspaper in terms of stereotypical depictions of age-related health conditions and assistive technology devices (ATDs). Four years (2009-2013) of Globe and Mail articles were searched for terms relevant to the research question. A total of 65 articles were retained, and a critical discourse analysis (CDA) of the texts was conducted. The articles were coded for stereotypes associated with age-related health conditions and ATDs, consequences of the stereotyping, and context (overall setting or background) of the discourse. The primary code list included 4 contexts, 13 stereotypes, and 9 consequences of stereotyping. CDA revealed discourses relating to (a) maintaining autonomy in a stereotypical world, (b) ATDs as obstacles in employment, (c) barriers to help seeking for age-related conditions, and (d) people in power setting the stage for discrimination. Our findings indicate that discourses in the Canadian media include stereotypes associated with age-related health conditions. Further, depictions of health conditions and ATDs may exacerbate existing stereotypes about older individuals, limit the options available to them, lead to a reduction in help seeking, and lower ATD use. Education about the realities of age-related health changes and ATDs is needed in order to diminish stereotypes and encourage ATD uptake and use. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Vacuum-assisted closure device enhances recovery of critically ill patients following emergency surgical procedures

    Science.gov (United States)

    2009-01-01

    Introduction Critically ill surgical patients frequently develop intra-abdominal hypertension (IAH) leading to abdominal compartment syndrome (ACS) with subsequent high mortality. We compared two temporary abdominal closure systems (Bogota bag and vacuum-assisted closure (VAC) device) in intra-abdominal pressure (IAP) control. Methods This prospective study with a historical control included 66 patients admitted to a medical and surgical intensive care unit (ICU) of a tertiary care referral center (Careggi Hospital, Florence, Italy) from January 2006 to April 2009. The control group included patients consecutively treated with the Bogota bag (Jan 2006-Oct 2007), whereas the prospective group was comprised of patients treated with a VAC. All patients underwent abdominal decompressive surgery. Groups were compared based upon their IAP, SOFA score, serial arterial lactates, the duration of having their abdomen open, the need for mechanical ventilation (MV) along with length of ICU and hospital stay and mortality. Data were collected from the time of abdominal decompression until the end of pressure monitoring. Results The Bogota and VAC groups were similar with regards to demography, admission diagnosis, severity of illness, and IAH grading. The VAC system was more effective in controlling IAP (P closure time (4.4 vs 6.6 days, P = 0.025), shorter duration of MV (7.1 vs 9.9 days, P = 0.039), decreased ICU length of stay (LOS) (13.3 vs 19.2 days, P = 0.024) and hospital LOS (28.5 vs 34.9 days; P = 0.019). Mortality rate did not differ significantly between the two groups. Conclusions Patients with abdominal compartment syndrome who were treated with VAC decompression had a faster abdominal closure rate and earlier discharge from the ICU as compared to similar patients treated with the Bogota bag. PMID:19961614

  12. Perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery

    Directory of Open Access Journals (Sweden)

    Meredith Degnan

    2016-01-01

    Full Text Available Aim: The aim of this study was to describe our institutional experience, primarily with general anesthesiologists consulting with cardiac anesthesiologists, caring for left ventricular assist device (LVAD patients undergoing noncardiac surgery. Materials and Methods: This is a retrospective review of the population of patients with LVADs at a single institution undergoing noncardiac procedures between 2009 and 2014. Demographic, perioperative, and procedural data collected included the type of procedure performed, anesthetic technique, vasopressor requirements, invasive monitors used, anesthesia provider type, blood product management, need for postoperative intubation, postoperative disposition and length of stay, and perioperative complications including mortality. Statistical Analysis: Descriptive statistics for categorical variables are presented as frequency distributions and percentages. Continuous variables are expressed as mean ± standard deviation and range when applicable. Results: During the study, 31 patients with LVADs underwent a total of 74 procedures. Each patient underwent an average of 2.4 procedures. Of the total number of procedures, 48 (65% were upper or lower endoscopies. Considering all procedures, 81% were performed under monitored anesthesia care (MAC. Perioperative care was provided by faculty outside of the division of cardiac anesthesia in 62% of procedures. Invasive blood pressure monitoring was used in 27 (36% procedures, and a central line, peripherally inserted central catheter or midline was in place preoperatively and used intraoperatively for 38 (51% procedures. Vasopressors were not required in the majority (65; 88% of procedures. There was one inhospital mortality secondary to multiorgan failure; 97% of patients survived to discharge after their procedure. Conclusion: At our institution, LVAD patients undergoing noncardiac procedures most frequently require endoscopy. These procedures can frequently be done

  13. Pre- and post-operative risk factors associated with cerebrovascular accidents in patients supported by left ventricular assist device. -Single center's experience in japan-.

    Science.gov (United States)

    Nakajima, Ikutaro; Kato, Tomoko S; Komamura, Kazuo; Takahashi, Ayako; Oda, Noboru; Sasaoka, Taro; Asakura, Masanori; Hashimura, Kazuhiko; Kitakaze, Masafumi

    2011-01-01

    Cerebrovascular accident (CVA) is a major adverse event following left ventricular assist device (LVAD) surgery. This study investigates pre- and post-operative factors associated with CVA in this population. A total of 118 consecutive patients who underwent LVAD surgery at our institution between April 1994 and April 2009 were retrospectively reviewed. Clinical characteristics, hemodynamic data, and laboratory indexes associated with CVA after LVAD surgery were analyzed. In total, 57 (48.3%) patients developed CVA 133.5 ± 184.7 days after surgery. The combination of baseline heart disease, type of LVAD surgery, mean right atrial pressure (mRA), serum total bilirubin and total protein concentration, and right ventricular end-diastolic dimension (RVEDd) was associated with CVA at any time after LVAD surgery, with a discriminant probability of 718%. With regard to CVA development later than 3 months after surgery, the combination of mRA and RVEDd before surgery [odds ratio (OR), 1.24, 1.20; 95% confidential interval (CI), 1.07-1.42, 1.06-1.34; P = 0.004, P = 0.006, respectively], positive blood culture, and C-reactive protein after surgery (OR, 7.66, 2.19; 95%CI, 1.50-39.0, 1.47-3.25; P = 0.015, P < 0.0001, respectively) was associated with CVA with a discriminant probability of 85.9%. Patients' general condition including malnutrition, in addition to device selection, contributed to overall CVA development after surgery. In the chronic phase after surgery, pre-LVAD right heart failure and post-LVAD systemic infection were highly associated with CVA development.

  14. Development of a rugged handheld device for real-time analysis of heart rate: entropy in critically ill patients.

    Science.gov (United States)

    Mejaddam, Ali Y; van der Wilden, Gwendolyn M; Chang, Yuchiao; Cropano, Catrina M; Sideris, Antonis C; Hwabejire, John O; Velmahos, George C; Alam, Hasan B; de Moya, Marc A; King, David R

    2013-01-01

    The usefulness of heart rate variability (HRV) and heart rate complexity (HRC) analysis as a potential triage tool has been limited by the inability to perform real-time analysis on a portable, handheld monitoring platform. Through a multidisciplinary effort of academia and industry, we report on the development of a rugged, handheld and noninvasive device that provides HRV and HRC analysis in real-time in critically ill patients. After extensive re-engineering, real-time HRV and HRC analyses were incorporated into an existing, rugged, handheld monitoring platform. Following IRB approval, the prototype device was used to monitor 20 critically ill patients and 20 healthy controls to demonstrate real-world discriminatory potential. Patients were compared to healthy controls using a Student?s t test as well as repeated measures analysis. Receiver operator characteristic (ROC) curves were generated for HRV and HRC. Critically ill patients had a mean APACHE-2 score of 15, and over 50% were mechanically ventilated and requiring vasopressor support. HRV and HRC were both lower in the critically ill patients compared to healthy controls (p analysis. The area under the ROC for HRV and HRC was 0.95 and 0.93, respectively. This is the first demonstration of real-time, handheld HRV and HRC analysis. This prototype device successfully discriminates critically ill patients from healthy controls. This may open up possibilities for real-world use as a trauma triage tool, particularly on the battlefield. 2013.

  15. Electromagnetic modelling of current flow in the heart from TASER devices and the risk of cardiac dysrhythmias

    Energy Technology Data Exchange (ETDEWEB)

    Holden, S J [Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ (United Kingdom); Sheridan, R D [Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ (United Kingdom); Coffey, T J [Mathshop Ltd, Porton Down Science Park, Salisbury, Wiltshire SP4 0JQ (United Kingdom); Scaramuzza, R A [Flomerics Ltd, Electromagnetic Division, TLM House, Percy Street, Nottingham NG16 3EP (United Kingdom); Diamantopoulos, P [Bio-Medical Modelling Unit, School of Engineering, University of Sussex, Falmer, Sussex BN1 9QT (United Kingdom)

    2007-12-21

    Increasing use by law enforcement agencies of the M26 and X26 TASER electrical incapacitation devices has raised concerns about the arrhythmogenic potential of these weapons. Using a numerical phantom constructed from medical images of the human body in which the material properties of the tissues are represented, computational electromagnetic modelling has been used to predict the currents arising at the heart following injection of M26 and X26 waveforms at the anterior surface of the chest (with one TASER 'barb' directly overlying the ventricles). The modelling indicated that the peak absolute current densities at the ventricles were 0.66 and 0.11 mA mm{sup -2} for the M26 and X26 waveforms, respectively. When applied during the vulnerable period to the ventricular epicardial surface of guinea-pig isolated hearts, the M26 and X26 waveforms induced ectopic beats, but only at current densities greater than 60-fold those predicted by the modelling. When applied to the ventricles in trains designed to mimic the discharge patterns of the TASER devices, neither waveform induced ventricular fibrillation at peak currents >70-fold (for the M26 waveform) and >240-fold (for the X26) higher than the modelled current densities. This study provides evidence for a lack of arrhythmogenic action of the M26 and X26 TASER devices.

  16. Electromagnetic modelling of current flow in the heart from TASER devices and the risk of cardiac dysrhythmias

    Science.gov (United States)

    Holden, S. J.; Sheridan, R. D.; Coffey, T. J.; Scaramuzza, R. A.; Diamantopoulos, P.

    2007-12-01

    Increasing use by law enforcement agencies of the M26 and X26 TASERTASER is an acronym for Thomas A. Swift's Electric Rifle from the book Tom Swift and His Electric Rifle (1911) by Victor Appleton, ISBN-10: 1594561257. electrical incapacitation devices has raised concerns about the arrhythmogenic potential of these weapons. Using a numerical phantom constructed from medical images of the human body in which the material properties of the tissues are represented, computational electromagnetic modelling has been used to predict the currents arising at the heart following injection of M26 and X26 waveforms at the anterior surface of the chest (with one TASER 'barb' directly overlying the ventricles). The modelling indicated that the peak absolute current densities at the ventricles were 0.66 and 0.11 mA mm-2 for the M26 and X26 waveforms, respectively. When applied during the vulnerable period to the ventricular epicardial surface of guinea-pig isolated hearts, the M26 and X26 waveforms induced ectopic beats, but only at current densities greater than 60-fold those predicted by the modelling. When applied to the ventricles in trains designed to mimic the discharge patterns of the TASER devices, neither waveform induced ventricular fibrillation at peak currents >70-fold (for the M26 waveform) and >240-fold (for the X26) higher than the modelled current densities. This study provides evidence for a lack of arrhythmogenic action of the M26 and X26 TASER devices.

  17. Successful Perioperative Management of a Patient with the Left Ventricular Assist Device for Brain Tumor Resection: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Rashmi Vandse

    2015-01-01

    Full Text Available Heart failure is the leading cause of death in the United States. Our increasingly aged population will contribute to an increased incidence and prevalence of heart failure, thereby augmenting the need for mechanical circulatory devices. Here we present the first successful resection of a brain tumor in a left ventricular device- (LVAD- dependent patient with increased intracranial pressure and address pertinent perioperative anesthetic considerations and management.

  18. Mathematical Modeling of a Blood Flow in Flow Path of the Axial Pump of Ventricular Assist Device

    OpenAIRE

    A. M. Guskov; F. D. Sorokin; E. P. Banin; A. E. Krupnin

    2015-01-01

    The research object is an axial left ventricular assist device (LVAD) design such as: straightener, impeller, and diffuser.The objective of the study is to reveal an influence of axial LVAD pump’s impeller design factors such as pitch and incidence on head-capacity curves and stagnation and hemolysis zones generation. The mathematical modeling is carried out by computational fluid dynamics analysis in a stationary setting.The study concentrates on mathematical modeling of a blood flow in flow...

  19. Ligament balancing in computer-assisted total knee arthroplasty: improved clinical results with a spring-loaded tensioning device.

    Science.gov (United States)

    Swank, M; Romanowski, J R; Korbee, L L; Bignozzi, S

    2007-10-01

    Total knee arthroplasty (TKA) remains one of the most successful procedures in orthopaedic surgery. Complications certainly exist and are often related to failure of knee ligament balance. This asymmetry subsequently leads to component mal-alignment and loosening often secondary to deviation of the lower extremity mechanical axis. Understanding knee mechanics is essential, and recent technological advances have begun to minimize postoperative problems. A tensioning device that respects the native patellofemoral anatomy as well as the natural ligamentous strains has been developed. The surgical integration of computer-assisted navigation has allowed for enhanced accuracy and subsequently better results. The purpose of the current paper is to discuss the evolution of an improved ligament tensioning device, in the setting of classic mechanical guidance versus computer assistance and its postoperative impact on total knee outcomes in terms of manipulation rates and two-year radiographic alignment data. Based on a single surgeon series, mechanically guided arthroplasties resulted in a 16 per cent manipulation rate. Computer assistance with spacer blocks decreased the manipulation rate to 14 per cent, while using a novel tensioner device further decreased the manipulation rate to 7 per cent, a significant difference of p tensioner to be within 4 degrees of the desired position.

  20. Design of a Code-Maker Translator Assistive Input Device with a Contest Fuzzy Recognition Algorithm for the Severely Disabled

    Directory of Open Access Journals (Sweden)

    Chung-Min Wu

    2015-01-01

    Full Text Available This study developed an assistive system for the severe physical disabilities, named “code-maker translator assistive input device” which utilizes a contest fuzzy recognition algorithm and Morse codes encoding to provide the keyboard and mouse functions for users to access a standard personal computer, smartphone, and tablet PC. This assistive input device has seven features that are small size, easy installing, modular design, simple maintenance, functionality, very flexible input interface selection, and scalability of system functions, when this device combined with the computer applications software or APP programs. The users with severe physical disabilities can use this device to operate the various functions of computer, smartphone, and tablet PCs, such as sending e-mail, Internet browsing, playing games, and controlling home appliances. A patient with a brain artery malformation participated in this study. The analysis result showed that the subject could make himself familiar with operating of the long/short tone of Morse code in one month. In the future, we hope this system can help more people in need.

  1. A new user-centered design approach: a hair washing assistive device design for users with shoulder mobility restriction.

    Science.gov (United States)

    Wu, Fong-Gong; Ma, Min-Yuan; Chang, Ro-Han

    2009-09-01

    This study utilized a user-centered design approach as the foundation for a new Assistive Device (AD) design process. Observation and evaluation results from a Usability Context Analysis (UCA) was used to improve the analysis of Strengths, Weaknesses, Opportunities and Threats (SWOT Analysis) and the matrix of Threats, Opportunities, Weaknesses, and Strengths (TOWS matrix), resulting in two assistive device design methods named AD-SWOT and AD-TOWS. Thus, an AD-design process, tailored for designing assistive devices, was both established and tested. Owing to the information gained from using the design processes and evaluating product efficiency with various cases in the early part of the research, it was decided to use the AD-design process for the entire design process. Using this process, an adjustable hair washer for physically disabled individuals to wash their hair using normal postures was developed. Furthermore, the method derived in this study can also be applied to users suffering from single-sided shoulder-joint mobility disabilities, such as frontal flexion, scapular plan elevation, and restricted abductors.

  2. The total artificial heart.

    Science.gov (United States)

    Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

    2015-12-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

  3. Short-term mechanical circulatory support as a bridge to durable left ventricular assist device implantation in refractory cardiogenic shock: a systematic review and meta-analysis.

    Science.gov (United States)

    den Uil, Corstiaan A; Akin, Sakir; Jewbali, Lucia S; Dos Reis Miranda, Dinis; Brugts, Jasper J; Constantinescu, Alina A; Kappetein, Arie Pieter; Caliskan, Kadir

    2017-07-01

    Short-term mechanical circulatory support (MCS) is increasingly used as a bridge to decision in patients with refractory cardiogenic shock. Subsequently, these patients might be bridged to durable MCS either as a bridge to candidacy/transplantation, or as destination therapy. The aim of this study was to review support duration and clinical outcome of short-term MCS in cardiogenic shock, and to analyse application of this technology as a bridge to long-term cardiac support (left ventricular assist device, LVAD) from 2006 till June 2016. Using Cochrane Register of Trials, Embase and Medline, a systematic review was performed on patients with cardiogenic shock from acute myocardial infarction, end-stage cardiomyopathy, or acute myocarditis, receiving short-term MCS. Studies on periprocedural, post-cardiotomy and cardiopulmonary resuscitation support were excluded. Thirty-nine studies, mainly registries of heterogeneous patient populations (n = 4151 patients), were identified. Depending on the device used (intra-aortic balloon pump, TandemHeart, Impella 2.5, Impella 5.0, CentriMag and peripheral veno-arterial extracorporeal membrane oxygenation), mean support duration was (range) 1.6-25 days and the mean proportion of short-term MCS patients discharged was (range) 45-66%. The mean proportion of bridge to durable LVAD was (range) 3-30%. Bridge to durable LVAD was most frequently performed in patients with end-stage cardiomyopathy (22 [12-35]%). We conclude that temporary MCS can be used to bridge patients with cardiogenic shock towards durable LVAD. Clinicians are encouraged to share their results in a large multicentre registry in order to investigate optimal device selection and best duration of support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  4. Ambulatory heart rate is underestimated when measured by an Ambulatory Blood Pressure device

    NARCIS (Netherlands)

    Vrijkotte, T.G.M.; de Geus, E.J.C.

    1999-01-01

    Objective: To test the validity of ambulatory heart rate (HR) assessment with a cuff ambulatory blood pressure (ABP) monitor. Design: Cross-instrument comparison of HR measured intermittently by a cuff ABP monitor (SpaceLabs, Redmond, Washington, USA), with HR derived from continuous

  5. Ambulatory heart rate is underestimated when measured by an ambulatory blood pressure device

    NARCIS (Netherlands)

    Vrijkotte, T.G.M.; de Geus, E.J.C.

    2001-01-01

    Objective: To test the validity of ambulatory heart rate (HR) assessment with a cuff ambulatory blood pressure (ABP) monitor. Design: Cross-instrument comparison of HR measured intermittently by a cuff ABP monitor (SpaceLabs, Redmond, Washington, USA), with HR derived from continuous

  6. Ambulatory heart rate is underestimated when measured by an ambulatory blood pressure device

    NARCIS (Netherlands)

    Vrijkotte, T. G.; de Geus, E. J.

    2001-01-01

    To test the validity of ambulatory heart rate (HR) assessment with a cuff ambulatory blood pressure (ABP) monitor. Cross-instrument comparison of HR measured intermittently by a cuff ABP monitor (SpaceLabs, Redmond, Washington, USA), with HR derived from continuous electrocardiogram (ECG) recordings

  7. Estimating Accuracy at Exercise Intensities: A Comparative Study of Self-Monitoring Heart Rate and Physical Activity Wearable Devices.

    Science.gov (United States)

    Dooley, Erin E; Golaszewski, Natalie M; Bartholomew, John B

    2017-03-16

    Physical activity tracking wearable devices have emerged as an increasingly popular method for consumers to assess their daily activity and calories expended. However, whether these wearable devices are valid at different levels of exercise intensity is unknown. The objective of this study was to examine heart rate (HR) and energy expenditure (EE) validity of 3 popular wrist-worn activity monitors at different exercise intensities. A total of 62 participants (females: 58%, 36/62; nonwhite: 47% [13/62 Hispanic, 8/62 Asian, 7/62 black/ African American, 1/62 other]) wore the Apple Watch, Fitbit Charge HR, and Garmin Forerunner 225. Validity was assessed using 2 criterion devices: HR chest strap and a metabolic cart. Participants completed a 10-minute seated baseline assessment; separate 4-minute stages of light-, moderate-, and vigorous-intensity treadmill exercises; and a 10-minute seated recovery period. Data from devices were compared with each criterion via two-way repeated-measures analysis of variance and Bland-Altman analysis. Differences are expressed in mean absolute percentage error (MAPE). For the Apple Watch, HR MAPE was between 1.14% and 6.70%. HR was not significantly different at the start (P=.78), during baseline (P=.76), or vigorous intensity (P=.84); lower HR readings were measured during light intensity (P=.03), moderate intensity (P=.001), and recovery (P=.004). EE MAPE was between 14.07% and 210.84%. The device measured higher EE at all stages (PGarmin Forerunner 225, HR MAPE was between 7.87% and 24.38%. HR was not significantly different at vigorous intensity (P=.35). The device measured higher HR readings at start, baseline, light intensity, moderate intensity (PGarmin Forerunner 225. An advantage and novel approach of the study is the examination of HR and EE at specific physical activity intensities. Establishing validity of wearable devices is of particular interest as these devices are being used in weight loss interventions and could

  8. The Resonating Arm Exerciser: design and pilot testing of a mechanically passive rehabilitation device that mimics robotic active assistance.

    Science.gov (United States)

    Zondervan, Daniel K; Palafox, Lorena; Hernandez, Jorge; Reinkensmeyer, David J

    2013-04-18

    Robotic arm therapy devices that incorporate actuated assistance can enhance arm recovery, motivate patients to practice, and allow therapists to deliver semi-autonomous training. However, because such devices are often complex and actively apply forces, they have not achieved widespread use in rehabilitation clinics or at home. This paper describes the design and pilot testing of a simple, mechanically passive device that provides robot-like assistance for active arm training using the principle of mechanical resonance. The Resonating Arm Exerciser (RAE) consists of a lever that attaches to the push rim of a wheelchair, a forearm support, and an elastic band that stores energy. Patients push and pull on the lever to roll the wheelchair back and forth by about 20 cm around a neutral position. We performed two separate pilot studies of the device. In the first, we tested whether the predicted resonant properties of RAE amplified a user's arm mobility by comparing his or her active range of motion (AROM) in the device achieved during a single, sustained push and pull to the AROM achieved during rocking. In a second pilot study designed to test the therapeutic potential of the device, eight participants with chronic stroke (35 ± 24 months since injury) and a mean, stable, initial upper extremity Fugl-Meyer (FM) score of 17 ± 8 / 66 exercised with RAE for eight 45 minute sessions over three weeks. The primary outcome measure was the average AROM measured with a tilt sensor during a one minute test, and the secondary outcome measures were the FM score and the visual analog scale for arm pain. In the first pilot study, we found people with a severe motor impairment after stroke intuitively found the resonant frequency of the chair, and the mechanical resonance of RAE amplified their arm AROM by a factor of about 2. In the second pilot study, AROM increased by 66% ± 20% (p = 0.003). The mean FM score increase was 8.5 ± 4 pts (p = 0.009). Subjects did not report

  9. The Resonating Arm Exerciser: design and pilot testing of a mechanically passive rehabilitation device that mimics robotic active assistance

    Science.gov (United States)

    2013-01-01

    Background Robotic arm therapy devices that incorporate actuated assistance can enhance arm recovery, motivate patients to practice, and allow therapists to deliver semi-autonomous training. However, because such devices are often complex and actively apply forces, they have not achieved widespread use in rehabilitation clinics or at home. This paper describes the design and pilot testing of a simple, mechanically passive device that provides robot-like assistance for active arm training using the principle of mechanical resonance. Methods The Resonating Arm Exerciser (RAE) consists of a lever that attaches to the push rim of a wheelchair, a forearm support, and an elastic band that stores energy. Patients push and pull on the lever to roll the wheelchair back and forth by about 20 cm around a neutral position. We performed two separate pilot studies of the device. In the first, we tested whether the predicted resonant properties of RAE amplified a user’s arm mobility by comparing his or her active range of motion (AROM) in the device achieved during a single, sustained push and pull to the AROM achieved during rocking. In a second pilot study designed to test the therapeutic potential of the device, eight participants with chronic stroke (35 ± 24 months since injury) and a mean, stable, initial upper extremity Fugl-Meyer (FM) score of 17 ± 8 / 66 exercised with RAE for eight 45 minute sessions over three weeks. The primary outcome measure was the average AROM measured with a tilt sensor during a one minute test, and the secondary outcome measures were the FM score and the visual analog scale for arm pain. Results In the first pilot study, we found people with a severe motor impairment after stroke intuitively found the resonant frequency of the chair, and the mechanical resonance of RAE amplified their arm AROM by a factor of about 2. In the second pilot study, AROM increased by 66% ± 20% (p = 0.003). The mean FM score increase was 8.5 ± 4 pts (p = 0

  10. LAPAROSCOPICALLY ASSISTED ANORECTOPLASTY AND THE USE OF THE BIPOLAR DEVICE TO SEAL THE RECTAL URINARY FISTULA.

    Science.gov (United States)

    Dutra, Robson Azevedo; Boscollo, Adriana Cartafina Perez

    2016-01-01

    The anorectal anomalies consist in a complex group of birth defects. Laparoscopic-assisted anorectoplasty improved visualization of the rectal fistula and the ability to place the pull-through segment within the elevator muscle complex with minimal dissection. There is no consensus on how the fistula should be managed. To evaluate the laparoscopic-assisted anorectoplasty and the treatment of the rectal urinary fistula by a bipolar sealing device. It was performed according to the original description by Georgeson1. Was used 10 mm infraumbilical access portal for 30º optics. The pneumoperitoneum was established with pressure 8-10 cm H2O. Two additional trocars of 5 mm were placed on the right and left of the umbilicus. The dissection started on peritoneal reflection using Ligasure(r). With the reduction in the diameter of the distal rectum was identified the fistula to the urinary tract. The location of the new anus was defined by the location of the external anal sphincter muscle complex, using electro muscle stimulator externally. Finally, it was made an anastomosis between the rectum and the new location of the anus. A Foley urethral probe was left for seven days. Seven males were operated, six with rectoprostatic and one with rectovesical fistula. The follow-up period ranged from one to four years. The last two patients operated underwent bipolar sealing of the fistula between the rectum and urethra without sutures or surgical ligation. No evidence of urethral leaks was identified. There are benefits of the laparoscopic-assisted anorectoplasty for the treatment of anorectal anomaly. The use of a bipolar energy source that seals the rectal urinary fistula has provided a significant decrease in the operating time and made the procedure be more elegant. As anomalias anorretais consistem de um grupo complexo de defeitos congênitos. A anorretoplastia laparoscópica permite melhor visualização da fístula retourinária e propicia o posicionamento do reto abaixado

  11. Implantable Medical Devices

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  12. Learner Perspectives Regarding Device Type in Technology-Assisted Language Learning

    Science.gov (United States)

    Ko, Myong-Hee

    2017-01-01

    This study compared learner perspectives regarding using PCs and smartphones as learning devices. A total of 167 Korean university students completed online assignments designed to maximize interaction with these devices. The assignments required students to submit their responses regarding assigned reading passages for a semester. Then they…

  13. Exercise Training in a Patient With a Left Ventricular Assist Device and Large Aortic Valve Thrombus.

    Science.gov (United States)

    Wuliya, Mijiti; Peyrot, Sandrine; Radu, Costin; Deux, Jean-François; Ben Elhaj, Habib; Lellouche, Nicolas; Damy, Thibaud; Guendouz, Soulef; Gellen, Barnabas

    2017-11-01

    An aortic valve thrombus (AVT) is a rare complication after HeartMate II implantation. In a 44-year-old man, a large AVT was discovered 6 weeks after implantation of a HeartMate II for severe dilated cardiomyopathy. The aortic valve was permanently closed. After a followup of 3 months without embolic events, the patient started a cardiac rehabilitation (CR) program involving aerobic exercise, resistance exercises, group gymnastics, and relaxation exercise, and completed the program without any complications, resulting in a significant functional benefit. CR might not be systematically contraindicated in patients with HeartMate II and an AVT, in particular, if there is no opening of the aortic valve at rest.

  14. Substrate type < 111 >-Cu{sub 2}O/<0001 >-ZnO photovoltaic device prepared by photo-assisted electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Zamzuri, Mohd, E-mail: zamzuri@tf.me.tut.ac.jp [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); School of Manufacturing Eng., Universiti Malaysia Perlis, Kampus Tetap Pauh Putra, Jln Arau-Changlun, 02600 Arau, Perlis (Malaysia); Sasano, Junji [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Mohamad, Fariza Binti [Faculty of Electrical & Electronic Eng., University Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor (Malaysia); Izaki, Masanobu [Department of Mechanical Eng., Toyohashi University of Technology, 1-1 Hibari Gaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)

    2015-11-30

    The substrate-type < 0001 > ZnO/<111 > Cu{sub 2}O photovoltaic (PV) device has been constructed by electrodeposition of a < 111 >-p-Cu{sub 2}O layer on an Au(111)/Si wafer substrate followed by stacking the n-ZnO layer by electrodeposition during light irradiation in aqueous solutions. The PV device was fabricated by stacking the Al:ZnO-window by sputtering and the top Al electrode by vacuum evaporation. The < 0001 >-ZnO layer was composed of aggregates of hexagonal columnar grains grown in the direction normal to the surface, and pores could be observed between the ZnO grains at the deposition time last 1800 s. The < 0001 >-ZnO/<111 >-Cu{sub 2}O PV device showed a photovoltaic performance under AM1.5 illumination, and showed the improved short-circuit current density of 5.87 mA cm{sup −2} by stacking the AZO-TCO due to the increase in the diffusion length of the carrier. - Highlights: • Substrate type ZnO/Cu{sub 2}O photovoltaic devices only by electrodeposition • ZnO layer was stacked on the Cu{sub 2}O layer by photo-assisted electrodeposition. • AZO/ZnO/Cu{sub 2}O photovoltaic devices with a short-circuit current density of 5.87 mA cm{sup −2}.

  15. Assessing symmetry using the mirror stand device with manual and software-assisted methods in postoperative zygomatic fracture patients

    Science.gov (United States)

    Syarif, A. N.; Bangun, K.

    2017-08-01

    Zygomatic fractures are among the most common fractures to the facial skeleton. However, because no standard and reliable method of evaluation is available to assess postoperative patients, we often rely on photographs and subjective assessments. A portable mirror stand device (MiRS), which is a new method for the standardization of photography, was developed in our institution. Used with image analysis software, this device provides a new method for evaluating outcomes after the open reduction and internal fixation of zygomatic fractures. The portable mirror stand device was set up in our outpatient clinic at the Cleft Craniofacial Center at Cipto Mangunkusumo Hospital. Photographs of 11 postoperative patients were taken using the device, and they were analyzed both manually and using image analysis software (ImageJ 1.46) for symmetry. The two methods were then compared to assess the correlation and agreement of the results. The measurements taken using the manual method and the software-assisted method did not differ significantly, which indicated the good agreement between the two methods. The results of the symmetry achieved atour center were similar to other centers in the Asian region (ΔZy = 3.4±1.5 mm, ΔBc = 2.6±1.6 mm, ΔCh = 2.3±2.4 mm) compared with (ΔZy = 3.2±1.7 mm, ΔBc = 2.6±1.6 mm, ΔCh = 2.3±2.5 mm). The treatment of zygomatic fracture a tour center achieved good results. The portable mirror stand device assisted the image analysis software (ImageJ 1.46), which could be beneficial in assessing symmetry in postoperative zygomatic fracture patients.

  16. What Are Some Types of Assistive Devices and How Are They Used?

    Science.gov (United States)

    ... movies and television programs. Barriers in community buildings, businesses, and workplaces can be removed or modified to ... impaired mobility or other disabilities drive motor vehicles . Family Center on Technology and Disability. (2012). Assistive technology ...

  17. The right ventricular failure risk score a pre-operative tool for assessing the risk of right ventricular failure in left ventricular assist device candidates

    National Research Council Canada - National Science Library

    Matthews, Jennifer Cowger; Koelling, Todd M; Pagani, Francis D; Aaronson, Keith D

    2008-01-01

    ...) failure in left ventricular assist device (LVAD) candidates. Right ventricular failure after LVAD surgery is associated with increased morbidity and mortality, but identifying LVAD candidates at risk for RV failure remains difficult...

  18. Initial experience with the Impella left ventricular assist device for postcardiotomy cardiogenic shock and unprotected left coronary artery angioplasty in patients with a low left ventricular ejection fraction

    National Research Council Canada - National Science Library

    Bautista-Hernández, Víctor; Gutiérrez, Francisco; Pinar, Eduardo; Gimeno, Juan R; Arribas, José M; García-Puente, Julio; Ray, Victor G; Arcas, Ramón; Valdés, Mariano

    2007-01-01

    .... Ventricular assist devices have been used to treat patients who suffer from postoperative cardiogenic shock despite use of an intraaortic balloon pump and maximum inotropic support. The Impella pump...

  19. [Design of a Front-end Device of Heart Rate Variability Analysis System Based on Photoplethysmography].

    Science.gov (United States)

    Shi, Lei; Sun, Peng; Pang, Yu; Luo, Zhiyong; Wang, Wei; Wang, Yanxiang

    2016-02-01

    Heart rate variability (HRV) is the difference between the successive changes in the heartbeat cycle, and it is produced in the autonomic nervous system modulation of the sinus node of the heart. The HRV is a valuable indicator in predicting the sudden cardiac death and arrhythmic events. Traditional analysis of HRV is based on a multielectrocardiogram (ECG), but the ECG signal acquisition is complex, so we have designed an HRV analysis system based on photoplethysmography (PPG). PPG signal is collected by a microcontroller from human's finger, and it is sent to the terminal via USB-Serial module. The terminal software not only collects the data and plot waveforms, but also stores the data for future HRV analysis. The system is small in size, low in power consumption, and easy for operation. It is suitable for daily care no matter whether it is used at home or in a hospital.

  20. Management of hidradenitis suppurativa wounds with an internal vacuum-assisted closure device.

    Science.gov (United States)

    Chen, Y Erin; Gerstle, Theodore; Verma, Kapil; Treiser, Matthew D; Kimball, Alexandra B; Orgill, Dennis P

    2014-03-01

    Hidradenitis suppurativa is a chronic, debilitating disease that is difficult to treat. Once medical management fails, wide local excision offers the best chance for cure. However, the resultant wound often proves too large or contaminated for immediate closure. The authors performed a retrospective chart review of hidradenitis cases managed surgically between 2005 and 2010. Data collected included patient characteristics, management method, and outcomes. Approximately half of the patients received internal vacuum-assisted closure therapy using the vacuum-assisted closure system and delayed closure and half of the patients received immediate primary closure at the time of their excision. Delayed closure consisted of closing the majority of the wound in a linear fashion following internal vacuum-assisted closure while accepting healing by means of secondary intention for small wound areas. Patients managed with internal vacuum-assisted closure had wounds on average four times larger in area than patients managed without internal vacuum-assisted closure. In both groups, all wounds were eventually closed primarily. Healing times averaged 2.2 months with internal vacuum-assisted closure and 2.7 months without. At an average follow-up time of 2.3 months, all patients with internal vacuum-assisted closure had no recurrence of their local disease. Severe hidradenitis presents a treatment challenge, as surgical excisions are often complicated by difficult closures and unsatisfactory recurrence rates. This study demonstrates that wide local excision with reasonable outcomes can be achieved using accelerated delayed primary closure. This method uses internal vacuum-assisted closure as a bridge between excision and delayed primary closure, facilitating closure without recurrence in large, heavily contaminated wounds. Therapeutic, III.

  1. Acquisition and integration of low vision assistive devices: understanding the decision-making process of older adults with low vision.

    Science.gov (United States)

    Copolillo, Al; Teitelman, Jodi L

    2005-01-01

    The purpose of this study was to describe how older adults with low vision make decisions to use low vision assistive devices (LVADs). Analysis of participants' narratives, from both group and individual interviews, revealed three topic areas affecting device use. Two are discussed in this paper: Experiences and Characteristics Leading to Successful LVAD Use Decision Making and Challenges to Successful LVAD Use Decision Making. The third, Adjustment to Low Vision Disability, is briefly discussed. Of particular importance to occupational therapy practitioners in the growing field of low vision rehabilitation was the value placed on low vision rehabilitation services to assist with acquiring devices and integrating them into daily routines. Occupational therapy services were highly regarded. Participants demonstrated the importance of becoming a part of a supportive network of people with low vision to gain access to information about resources. They emphasized the need for systems and policy changes to reduce barriers to making informed decisions about LVAD use. Results indicate that occupational therapists working in low vision can support clients by facilitating development of a support network, acting as liaisons between clients and other health practitioners, especially ophthalmologists, and encouraging policy development that supports barrier-free LVAD acquisition and use. These topics should be incorporated into continuing and entry-level education to prepare practitioners for leadership in the field of low vision rehabilitation.

  2. Portable Heart Rate Detector Based on Photoplethysmography with Android Programmable Devices for Ubiquitous Health Monitoring System

    Directory of Open Access Journals (Sweden)

    Chi Kin Lao

    2013-01-01

    Full Text Available In this paper, a miniature portable heart rate detector system is implemented by modern hardware ICs and simple sensor circuit with software executable on both PC and Android platform. The biosignal is first extracted via photoplethysmography (PPG principle into electric signal. Then a microprocessor is used to covert biosignal from analog to digital format, suitably for feeding into an RF module (nRF24L01 for RF transmission. On the receiver end, the computer and/or smart phone can analyze the data using a robust algorithm that can detect peaks of the PPG waveform, hence to calculating the heart rate. Some application software running on Windows and Android phone have been developed to display heart rate information and time domain waveform to users for health care monitoring. In the future, pure Bluetooth technology will be used for wireless personal communications instead of RF modules. At the same time, the data can be sent to computer console using existing available networks (3G, 4G, WiFi, etc. for health database logging purpose.

  3. Prevalence of patent foramen ovale and usefulness of percutaneous closure device in carcinoid heart disease.

    Science.gov (United States)

    Mansencal, Nicolas; Mitry, Emmanuel; Pillière, Rémy; Lepère, Céline; Gérardin, Benoît; Petit, Jérôme; Gandjbakhch, Iradj; Rougier, Philippe; Dubourg, Olivier

    2008-04-01

    The aim of this study was to assess (1) the incidence of patent foramen ovale (PFO) in carcinoid syndrome (CS) and (2) the feasibility of percutaneous closure procedure in selected patients with CS. One hundred eight patients were prospectively studied: 54 with CS and an age- and gender-matched control group. All patients underwent conventional and contrast echocardiography. Patients with clinical signs of dyspnea (New York Heart Association class > or =III), cyanosis, carcinoid heart disease (CHD), and severe PFO were referred for the percutaneous closure of PFO. The prevalence of PFO was 41% in patients with CS and 22% in the control group (p = 0.03) and was significantly higher in patients with CHD (59%, p = 0.009). Four patients (14% of those with CHD) were referred for the percutaneous closure of PFO, and 3 patients ultimately underwent PFO closure (using Amplatzer septal occluders). At 6-month follow-up, New York Heart Association class was improved in all patients, as well as arterial blood gas results (p = 0.04) and 6-minute walking distance (p = 0.03), but all patients presented residual right-to-left shunts. In conclusion, this prospective study demonstrates that in patients with CHD, the prevalence of PFO is high and that percutaneous closure of PFO is feasible, with a reduction in symptoms but with residual shunting.

  4. Clinical Usefulness of a Mobile Application for the Appropriate Selection of the Antiarrhythmic Device in Heart Failure.

    Science.gov (United States)

    Curcio, Antonio; DE Rosa, Salvatore; Sabatino, Jolanda; DE Luca, Simona; Bochicchio, Angela; Polimeni, Alberto; Santarpia, Giuseppe; Ricci, Pietrantonio; Indolfi, Ciro

    2016-07-01

    Appropriate selection of implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device can be challenging in patients with left ventricular (LV) dysfunction. In this setting, limited information exists about the role of medical applications in helping physicians to choose the most useful device. We developed a medical application that provides guidelines-based algorithms for helping doctors in decision process using the Apache Cordova application programming interface. e-CRTD App was tested in 36 consecutive patients (age 66.4 ± 8.5 years, 31 males) with diagnosis of heart failure (HF) addressed to electrophysiology laboratory for evaluation of ICD (N = 18) or CRT with defibrillator device (CRT-D; N = 18) implantation. Two separate teams evaluated each patient independently: expert electrophysiologists (Group A); cardiologists in training using the App (Group B). The outcomes of the clinical evaluation performed by Groups A and B were similar in 100% of patients in terms of classes of recommendations to device (Class I in eight cases, Class IIa in seven cases, Class III in the remaining 21). Surprisingly, the majority of indications from the general practitioners to cardiac device were inappropriate (N = 17 ICD, and N = 4 CRT-D, Class III); nevertheless, e-CRTD App helped Group B (nonexpert cardiologists) in excluding all these cases. This study describes and validates a mobile application realized to help the decision-making process in HF patients candidate to ICD/CRT-D. This application supports physicians to assess the eligibility for ICD or CRT-D according to current guidelines in patients with LV dysfunction. © 2016 Wiley Periodicals, Inc.

  5. Use of the Impella 2.5 left ventricular assist device in a patient with cardiogenic shock secondary to takotsubo cardiomyopathy

    OpenAIRE

    Rashed, Ahmed; Won, Sekon; Saad, Marwan; Schreiber, Theodore

    2015-01-01

    We report a case of cardiogenic shock, believed to be secondary to stress-induced cardiomyopathy, managed by an Impella 2.5 assist device. Apical ballooning pattern was evident on left ventriculogram with no significant coronary artery disease on coronary angiography. Cardiogenic shock was initially managed medically with inotropes and vasopressors, but because the patient was clinically deteriorating, an Impella 2.5 left ventricular assist device was implanted. Remarkable recovery occurred w...

  6. Risk factors for the development of right ventricular failure after left ventricular assist device implantation-a single-centre retrospective with focus on deformation imaging.

    Science.gov (United States)

    Boegershausen, Nadia; Zayat, Rashad; Aljalloud, Ali; Musetti, Giulia; Goetzenich, Andreas; Tewarie, Lachmandath; Moza, Ajay; Amerini, Andrea; Autschbach, Rüdiger; Hatam, Nima

    2017-12-01

    Right heart failure (RHF) after the implantation of a left ventricular assist device (LVAD) remains a dreaded postoperative complication. Using 2D speckle-tracking echocardiography, it is possible to acquire right ventricular global and regional function. The aim of our study was to assess whether speckle-tracking echocardiography values will better predict the RHF post-continuous-flow LVAD implantation. From January 2014 to January 2016, 54 patients who underwent LVAD implantation were included and retrospectively analysed. Clinical, invasive haemodynamic (right and left heart catheterization), laboratory and transthoracic echocardiography data were reviewed. Multivariable logistic regression was performed using RHF as dependent variable. Thirteen patients (24%) developed RHF. These patients had significantly elevated procalcitonin (P = 0.011), elevated central venous pressure (CVP) pre- and post-LVAD implantation (P = 0.002 and 0.031, respectively), higher right ventricular (RV) and pulmonary systolic pressure (P = 0.016 and 0.013, respectively), higher Michigan Risk Score (P = 0.001) and a lower peak systolic longitudinal strain of the basal RV free wall (P = 0.032). Haemoglobin, procalcitonin, RV systolic pressure, basal right ventricular free wall and pre-CVP entered the final multivariable analysis, only basal right ventricular free wall (P RHF. The sensitivity and specificity of the final model were 85.7% and 95.4%, respectively. The negative predictive value reached 94%. 2D strain parameters of the RV free wall seem to be auspicious for RV function and predicting RHF. Moreover, intraoperative CVP should not be neglected since elevated values proved to be highly associated with RHF. Our results represent a valuable supplement to other scores by considering both echocardiography and intraoperative data.

  7. The Use of Eptifibatide Alone or in Combination With Heparin or Argatroban for Suspected Thrombosis in Patients With Left Ventricular Assist Devices.

    Science.gov (United States)

    Bitar, Abbas; Vijayakrishnan, Rajakrishnan; Lenneman, Andrew; Birks, Emma; Massey, Todd; Slaughter, Mark; Abramov, Dmitry

    2017-12-01

    Pump thrombosis and hemolysis in patients with left ventricular assist devices (LVADs) are associated with significant morbidity and mortality. Intensification of anticoagulation has been suggested as potential therapy, with mixed results. The aim of this study is to assess the safety and efficacy of adding eptifibatide with or without an anticoagulation agent in managing patients with LVAD presenting with hemolysis and suspected pump thrombosis. This retrospective single center study included all patients who presented with their first episode of suspected pump thrombosis and were treated with eptifibatide with or without an anticoagulant between March 1, 2011 and July 30, 2015. A total of 27 patients (23 HeartMate II, 4 HeartWare) were identified. The average age was 55 years (range 19-75) and time from implant to event averaged 513 days (range 35-1760). The average lactate dehydrogenase on presentation was 1111 and 63% of patients had power elevations. The average international normalized ratio (INR) on admission was 2.4, with INR of ≥2 in 21/27 patients. All patients received eptifibatide: 10 received eptifibatide only, 9 received eptifibatide and argatroban, and 8 received eptifibatide and heparin. Warfarin was continued in 25/27 patients. Overall, 21 patients (77.8%) were successfully treated medically, 5 (18.5%) underwent pump exchange, and 1 (3.7%) died. There were no differences in outcomes or complications between the three treatment groups. Despite initial success, 12/21 patients developed repeat episodes of hemolysis at 1 year. The 1-year survival in the patients treated medically was 90% and surgically was 60%. Our experience indicates that medical therapy for hemolysis and suspected LVAD thrombosis with warfarin and eptifibatide alone or in combination with argatroban or heparin appears safe and may be effective, although the episodes of recurrent hemolysis after medical management remain high. © 2017 International Center for Artificial Organs and

  8. Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

    KAUST Repository

    In, Jung Bin

    2012-09-25

    We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications. © 2012 American Chemical Society.

  9. Impact of Patient Distance From Ventricular Assist Device-Implanting Center on Short- and Long-Term Outcomes.

    Science.gov (United States)

    Ravichandran, Ashwin K; Shah, Palak; Singh, Ramesh; Aaronson, Keith D; Pagani, Francis D; Stulak, John; Dunlay, Shannon M; Dardas, Todd F; Mokadam, Nahush A; Salerno, Christopher T; Cowger, Jennifer A

    2017-11-07

    Highly specialized left ventricular assist device care is not readily available in many areas, potentially limiting access to therapy. This retrospective analysis examines the relationship of outcomes by patient distance from implanting left ventricular assist device center within the Mechanical Circulatory Support Research Network. Zip codes were used to calculate patient distance, with the primary outcome of interest being 3-year survival by distance from the surgical center. Secondary outcomes included 90-day survival and incident event rates for the following: gastrointestinal bleeding, infection, cerebral event, and pump thrombosis. Across the four centers, there were 1184 patients supported for a median of 486 days. Overall survival was 91 ± 0.8% at 90 days and 61 ± 1.9% at 3 years, with worse 3-year survival in those living >90 vs. ≤90 miles from the ventricular assist device implant center (55 ± 3.0% vs. 64 ± 2.5, p = 0.019). Patients living >90 miles from an implant center were older, more likely to be implanted for destination therapy support, had a prior sternotomy, and had worse renal function than those living closer (p <0.05 for all). After adjusting for these factors, albumin and center of implant, the hazard ratio did not reach statistical significance (hazard ratio = 1.2; p = 0.14). Except for gastrointestinal bleeding, the event rates for the secondary outcomes were higher for those living closer to the implanting center. Protocols should be designed for more frequent follow-up and increased shared care opportunities to ensure optimal outcomes are achieved in distant patients.

  10. Utility of a novel biofeedback device for within-breath modulation of heart rate in rats: a quantitative comparison of vagus nerve versus right atrial pacing.

    Directory of Open Access Journals (Sweden)

    Erin Louise O'Callaghan

    2016-02-01

    Full Text Available In an emerging bioelectronics era, there is a clinical need for physiological devices incorporating biofeedback that permits natural and demand-dependent control in real time. Here, we describe a novel device termed a central pattern generator (CPG that uses cutting edge analogue circuitry producing temporally controlled, electrical stimulus outputs based on the real time integration of physiological feedback. Motivated by the fact that respiratory sinus arrhythmia (RSA, which is the cyclical changes in heart rate every breath, is an essential component of heart rate variability (an indicator of cardiac health, we have explored the versatility and efficiency of the CPG for producing respiratory modulation of heart rate in anaesthetised, spontaneously breathing rats. Diaphragmatic electromyographic activity was used as the input to the device and its output connected to either the right cervical vagus nerve or the right atrium for pacing heart rate. We found that the CPG could induce respiratory related heart rate modulation that closely mimicked RSA. Whether connected to the vagus nerve or right atrium, the versatility of the device was demonstrated by permitting: (i heart rate modulation in any phase of the respiratory cycle, (ii control of the magnitude of heart rate modulation and (iii instant adaptation to changes in respiratory frequency. Vagal nerve pacing was only possible following transection of the nerve limiting its effective use chronically. Pacing via the right atrium permitted better flexibility and control of heart rate above its intrinsic level. This investigation now lays the foundation for future studies using this biofeedback technology permitting closer analysis of both the function and dysfunction of RSA.

  11. A transcatheter intracardiac shunt device for heart failure with preserved ejection fraction (REDUCE LAP-HF)

    DEFF Research Database (Denmark)

    Hasenfuß, Gerd; Hayward, Chris; Burkhoff, Dan

    2016-01-01

    was an open-label, single-arm, phase 1 study designed to assess the performance and safety of a transcatheter interatrial shunt device (IASD, Corvia Medical, Tewkesbury, MA, USA) in patients older than 40 years of age with symptoms of HFPEF despite pharmacological therapy, left ventricular ejection fraction...

  12. Development and control of a magnetorheological haptic device for robot assisted surgery.

    Science.gov (United States)

    Shokrollahi, Elnaz; Goldenberg, Andrew A; Drake, James M; Eastwood, Kyle W; Kang, Matthew

    2017-07-01

    A prototype magnetorheological (MR) fluid-based actuator has been designed for tele-robotic surgical applications. This device is capable of generating forces up to 47 N, with input currents ranging from 0 to 1.5 A. We begin by outlining the physical design of the device, and then discuss a novel nonlinear model of the device's behavior. The model was developed using the Hammerstein-Wiener (H-W) nonlinear black-box technique and is intended to accurately capture the hysteresis behavior of the MR-fluid. Several experiments were conducted on the device to collect estimation and validation datasets to construct the model and assess its performance. Different estimating functions were used to construct the model, and their effectiveness is assessed based on goodness-of-fit and final-prediction-error measurements. A sigmoid network was found to have a goodness-of-fit of 95%. The model estimate was then used to tune a PID controller. Two control schemes were proposed to eliminate the hysteresis behavior present in the MR fluid device. One method uses a traditional force feedback control loop and the other is based on measuring the magnetic field using a Hall-effect sensor embedded within the device. The Hall-effect sensor scheme was found to be superior in terms of cost, simplicity and real-time control performance compared to the force control strategy.

  13. Osteopathic treatment in a patient with left-ventricular assist device with left brachialgia: a case report.

    Science.gov (United States)

    Bordoni, Bruno; Marelli, Fabiola; Morabito, Bruno; Sacconi, Beatrice

    2017-01-01

    This study deals with an osteopathic approach used for a patient with left-ventricular assist device (L-VAD) affected by left brachialgia. Clinical examination revealed the presence of thoracic outlet syndrome and pectoralis minor syndrome, with compression of the left proximal ulnar nerve, related to the surgical sternotomy performed. The osteopathic techniques used can be classified as indirect and direct, addressed to the pectoralis minor and the first left rib, respectively. To our knowledge, this is the first text in literature with an osteopathic treatment in a patient with L-VAD.

  14. Massive Atenolol, Lisinopril, and Chlorthalidone Overdose Treated with Endoscopic Decontamination, Hemodialysis, Impella Percutaneous Left Ventricular Assist Device, and ECMO.

    Science.gov (United States)

    Heise, C William; Beutler, David; Bosak, Adam; Orme, Geoffrey; Loli, Akil; Graeme, Kimberlie

    2015-03-01

    Overdose of cardiovascular medications is increasingly associated with morbidity and mortality. We present a case of substantial atenolol, chlorthalidone, and lisinopril overdose treated by multiple modalities with an excellent outcome. Aggressive medical intervention did not provide sufficient hemodynamic stability in this patient with refractory cardiogenic and distributive shock. Impella® percutaneous left ventricular assist device and extracorporeal membrane oxygenation provided support while the effects of the overdose subsided. We present concentrations demonstrating removal of atenolol with continuous venovenous hemodiafiltration. This is the first report of esophagogastroduo denoscopy decontamination of this overdose with a large pill fragment burden.

  15. Platelet factor 4-positive thrombi adhering to the ventricles of a ventricular assist device in patients with heparin-induced thrombocytopenia type II.

    Science.gov (United States)

    Beiras-Fernandez, A; Kanzler, I; Michel, S; Sadoni, S; Kilger, E; Beiras, A; Kur, F

    2013-06-01

    Thromboembolism is a major complication in patients with ventricular assist devices (VADs). Drug anticoagulation and the use of biocompatible surfaces, such as coating with heparin, aim to reduce thromboembolism in these patients. Administration of heparin can lead to heparin-induced thrombocytopenia (HIT) type II, mainly through heparin/platelet factor 4 (PF4) antibodies. We assessed the presence of PF4 antibodies in VAD thrombi of patients with heparin-coated VADs and HIT II. Thrombi (n = 6) were obtained from the replaced Excor ventricles of patients with HIT II after biventricular VAD implantation (Excor Adult; Berlin Heart, Germany). Excor ventricles were changed after clinical examination and suspicion of thrombi in the polyurethane valves. Expression of PF4- antibodies was assessed with the use of a polyclonal rabbit antibody (anti-PF4 antibody; Abcam, USA). Expression was assessed by 2 independent observers. Biopsies of all thrombi showed an extreme positive immunoreaction for PF4. No differences between the different thrombi and localization (left/right Excor ventricle) were observed. The thrombi were organized, without lamination of fibrin and cellular layers. Platelet surface expression of PF4 in the thrombi reflects HIT antigen presentation. The physical relationship between the PF4-positive thrombi and the heparin-coated surface suggests that onset of HIT II could be influenced by the immobilized heparin coating. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Serum Brain Natriuretic Peptide Concentration 60 Days after Surgery as a Predictor of Long-term Prognosis in Patients Implanted with a Left Ventricular Assist Device.

    Science.gov (United States)

    Sato, Takuma; Seguchi, Osamu; Iwashima, Yoshio; Yanase, Masanobu; Nakajima, Seiko; Hieda, Michinari; Watanabe, Takuya; Sunami, Haruki; Murata, Yoshihiro; Hata, Hiroki; Fujita, Tomoyuki; Kobayashi, Junjiro; Nakatani, Takeshi

    2015-04-23

    Mechanical circulatory support by a left ventricular assist device (LVAD) is used to bridge patients with advanced heart failure to transplant or as a definitive treatment. We retrospectively sought predictors of long-term outcome in a cohort of 83 patients who had undergone LVAD treatment. We subjected patients' perioperative clinical data to statistical analysis to establish parameters associated with all-cause mortality, and the cut-off values, sensitivity and specificity of those that had a statistically significant relationship with survival. Mean follow up was 717 days (standard deviation 334 days, range 17-1592 days). Fourteen patients (16.8%) died, but nine (10.8%) were weaned from support. Serum brain natriuretic peptide (BNP) concentration measured 60 days after implantation was significantly associated with all-cause mortality. The optimal BNP cut-off value to predict death during LVAD support was 322 pg/ml, with a sensitivity of 71.4% and specificity of 79.8%. Two-year survival was 92.0% in those with 60-day serum BNP concentration Creative Commons Attribution-Non Commercial-No Derivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.

  17. A delayed splenic rupture after transcatheter arterial embolization required total splenectomy in a patient with an implantable left ventricular assist device.

    Science.gov (United States)

    Kitahara, Hiroto; Nawata, Kan; Kinoshita, Osamu; Itoda, Yoshifumi; Kimura, Mitsutoshi; Yamauchi, Haruo; Ono, Minoru

    2016-12-01

    We successfully managed a splenic injury and delayed splenic rupture in a patient with an implantable left ventricular assist device (iLVAD). A 42-year-old man with an iLVAD for idiopathic dilated cardiomyopathy was admitted to our department complaining of dizziness. Laboratory data showed severe anemia, and computed tomography demonstrated a traumatic splenic injury. Following conservative treatment, partial splenic embolization was performed. Fifteen days after the intervention, the patient went into hemorrhagic shock due to delayed splenic rupture. Emergency total splenic embolization was performed, and total splenectomy was conducted later to prevent re-bleeding or abscess formation. His postoperative course was uneventful, and he was discharged on postoperative day 22. Finally, he underwent orthotropic heart transplantation without post-splenectomy sepsis or thrombotic complications 472 days after splenectomy. Splenic injury should be considered as a possible complication of iLVAD. In addition, careful follow-up after transcatheter arterial embolization for splenic injury is essential for managing delayed splenic rupture.

  18. Usefulness of Speckle Tracking Strain Echocardiography for Assessment of Risk of Ventricular Arrhythmias After Placement of a Left Ventricular Assist Device.

    Science.gov (United States)

    Akhabue, Ehimare; Seok Park, Chan; Pinney, Sean; Anyanwu, Anelechi; Chaudhry, Farooq; Narula, Jagat; Nair, Ajith; Sengupta, Partho P

    2017-11-01

    Patients with continuous-flow left ventricular assist devices (LVADs) are at elevated risk of developing ventricular arrhythmias (VA), which can result in right ventricular dysfunction and abnormal LVAD function. Predictors of postoperative VA after LVAD placement are unclear. We hypothesized that global left ventricular circumferential strain (LVCS), a marker of transmural impairment in myocardial function, would independently predict postoperative VA in patients who underwent LVAD implantation. We studied 98 consecutive patients (57 ± 11 years, 83% men) who underwent HeartMate II axial flow LVAD placement. Speckle tracking-derived global circumferential strain was assessed from mid-left ventricular short-axis images. The primary composite end point was defined as any ventricular tachycardia that required intervention (anti-arrhythmic medication, cardioversion, implantable cardioverter defibrillator placement, implantable cardioverter defibrillator shock) or any ventricular fibrillation. A total of 33 patients (34%) experienced the primary end point (median follow-up: 7 months). Reduced LVCS was statistically significantly related to the primary end point (hazard ratio 1.77, 95% confidence interval 1.09 to 2.87 per 1 standard deviation reduction in LVCS, p = 0.02). LVCS above a cut-off value of -9.7% was associated with significantly reduced arrhythmia-free survival (log-rank p = 0.001). In conclusion, global LVCS is an independent predictor of ventricular arrhythmias after LVAD placement. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Integrated SDS removal and protein digestion by hollow fiber membrane based device for SDS-assisted proteome analysis.

    Science.gov (United States)

    Xia, Simin; Yuan, Huiming; Chen, Yuanbo; Liang, Zheng; Zhang, Lihua; Zhang, Yukui

    2015-08-15

    In this work, a novel integrated sample preparation device for SDS-assisted proteome analysis was developed, by which proteins dissolved in 4% (w/v) SDS were first diluted by 50% methanol, and then SDS was online removed by a hollow fiber membrane interface (HFMI) with 50mM ammonium bicarbonate (pH 8.0) as an exchange buffer, finally digested by an immobilized enzyme reactor (IMER). To evaluate the performance of such an integrated device, bovine serum albumin dissolved in 4% (w/v) SDS as a model sample was analyzed; it could be found that similar to that obtained by direct analysis of BSA digests without SDS (the sequence coverage of 60.3±1.0%, n=3), with HFMI as an interface for SDS removal, BSA was identified with the sequence coverage of 61.0±1.0% (n=3). However, without SDS removal by HFMI, BSA could not be digested by the IMER and none peptides could be detected. In addition, such an integrated sample preparation device was also applied for the analysis of SDS extracted proteins from rat brain, compared to those obtained by filter-aided sample preparation (FASP), not only the identified protein group and unique peptide number were increased by 12% and 39% respectively, but also the sample pretreatment time was shortened from 24h to 4h. All these results demonstrated that such an integrated sample preparation device would provide an alternative tool for SDS assisted proteome analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. A novel device based on smart textile to control heart's activity during exercise.

    Science.gov (United States)

    Romagnoli, Marco; Alis, Rafael; Guillen, Javier; Basterra, Javier; Villacastin, J P; Guillen, Sergio

    2014-06-01

    In recent years, several systems have been developed to control cardiac function during exercise, and some are also capable of recording RR data to provide heart rate variability (HRV) analyses. In this study we compare time between heart beats and HRV parameters obtained with a smart textile system (GOW; Weartech sl., Spain) and an electrocardiogram machine commonly used in hospitals during continuous cycling tests. Twelve cardiology patients performed a 30-min cycling test at stable submaximal intensity. RR interval data were recorded during the test by both systems. 3-min RR segments were taken to compare the time intervals between beats and HRV variables using Bland-Altman analyses and intraclass correlation coefficients. Limits of agreement (LoAs) on RR intervals were stable at around 3 ms (widest LoAs -5.754 to 6.094 ms, tightest LoAs -2.557 to 3.105 ms, medium LoAs -3.638 ± 0.812 to 3.145 ± 0.539 ms). HRV parameters related to short-term change presented wide LoAs (RMSSD -0.17 to 18.41 %, HF -17.64 to 33.21 %, SD1 -0.50 to 17.54 %) as an effect of the error measurement of the GOW system. The GOW system is a valid tool for controlling HR during physical activity, although its use as a clinical tool for HRV cannot be supported.

  1. Management of intracranial hemorrhage in a child with a left ventricular assist device.

    Science.gov (United States)

    Haque, Raqeeb; Wojtasiewicz, Teresa; Gerrah, Rabin; Gilmore, Lisa; Saiki, Yoshikatsu; Chen, Jonathan M; Richmond, Marc; Feldstein, Neil A; Anderson, Richard C E

    2012-08-01

    Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are at increased risk of hemorrhagic complications, including intracranial hemorrhage. In this population, intracranial hemorrhage is often fatal. We report a case of successful management of a five-yr-old-boy with DCM on an LVAD who developed a subdural hematoma. We initially chose medical management, weighing the patient's high risk of thromboembolism from anticoagulation reversal against the risk of his chronic subdural hematoma. When head CT showed expansion of the hemorrhage with increasing midline shift, we chose prompt surgical evacuation of the hematoma with partial reversal of anticoagulation, given the increased risk of acute deterioration. The patient ultimately received an orthotopic heart transplant and was discharged with no permanent neurological complications. This represents a case of a pediatric patient on an LVAD who survived a potentially fatal subdural hematoma and was successfully bridged to cardiac transplantation. © 2012 John Wiley & Sons A/S.

  2. Failing Systemic Right Ventricles With Persistent Pulmonary Hypertension: Candidates for Ventricular Assist Devices as Destination Therapy?

    Science.gov (United States)

    Loup, Ophelie; Wustmann, Kerstin; Martinelli, Michele Vittorio; Schwerzmann, Markus; Mohacsi, Paul; Carrel, Thierry Pierre; Kadner, Alexander

    2017-02-01

    Dysfunction of the systemic right ventricle is common after the atrial switch procedure for transposition of the great arteries. Cardiac transplantation remains the only long-term solution in terminal systemic right ventricular (RV) failure, but concomitant pulmonary hypertension (PHT) may preclude it. The increasing number of such patients, together with the concerns related to combined heart-lung transplantation (HLTx), urge us to consider other therapeutic options. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Decision making for destination therapy left ventricular assist devices: "there was no choice" versus "I thought about it an awful lot".

    Science.gov (United States)

    McIlvennan, Colleen K; Allen, Larry A; Nowels, Carolyn; Brieke, Andreas; Cleveland, Joseph C; Matlock, Daniel D

    2014-05-01

    Destination therapy left ventricular assist devices (DT LVADs) are one of the most invasive medical interventions for end-stage illness. How patients decide whether or not to proceed with device implantation is unknown. We aimed to understand the decision-making processes of patients who either accept or decline DT LVADs. Between October 2012 and September 2013, we conducted semistructured, in-depth interviews to understand patients' decision-making experiences. Data were analyzed using a mixed inductive and deductive approach. Twenty-two eligible patients were interviewed, 15 with DT LVADs and 7 who declined. We found a strong dichotomy between decision processes with some patients (11 accepters) being automatic and others (3 accepters, 7 decliners) being reflective in their approach to decision making. The automatic group was characterized by a fear of dying and an over-riding desire to live as long as possible: "[LVAD] was the only option I had…that or push up daisies…so I automatically took this." By contrast, the reflective group went through a reasoned process of weighing risks, benefits, and burdens: "There are worse things than death." Irrespective of approach, most patients experienced the DT LVAD decision as a highly emotional process and many sought support from their families or spiritually. Some patients offered a DT LVAD face the decision by reflecting on a process and reasoning through risks and benefits. For others, the desire to live supersedes such reflective processing. Acknowledging this difference is important when considering how to support patients who are faced with this complex decision. © 2014 American Heart Association, Inc.

  4. Right Ventricular Function in Patients With Left Ventricular Assist Device Support by Pulsatile Polvad MEV and Continuous-Flow Pumps Heartware and Heartmate II.

    Science.gov (United States)

    Nadziakiewicz, P; Borkowski, J; Szygula-Jurkiewicz, B; Niklewski, T; Pacholewicz, J; Zakliczynski, M; Hrapkowicz, T; Zembala, M

    2016-06-01

    Left ventricular assist device (LVAD) support is increasingly used in patients with heart failure. The right ventricle (RV) plays a main role in LVAD support. Little is known about the effects of pulsatile Polvad MEV devices or continuouseconds flow pumps on RV function. We compared hemodynamic parameters of RV in patients after implantation of Polvad MEV (PM) and Heartware (HW) or Heartmate II (HMII) LVADs. Forty-four patients were retrospectively reviewed after implantation of PM (group P; n = 24 [21 M, 3 F]) or HW or HMII (group C; n = 20 [20 M, 0 F]) LVADs from April 2007 to February 2014. Hemodynamic data-mean pulmonary pressure (mPAP), central venous pressure (CVP), cardiac output (CO), and cardiac index (CI)-were collected before surgery, after surgery, and every 2 hours in the intensive care unit, with the time points numbered from 1 to 120. Right ventricular work (RVW) was calculated according to the equation: RCW = CO × (mPAP - CVP) × 0.0144 (g·m). Baseline characteristic of the patients were similar. mPAP values were similar between groups. CVP values were higher in group P, significantly at time points 5 and 7-33. CO values were higher in group C, significantly from point 3 and almost all the time to point 43. CI reached significance at point 9, 12-14, 16-19, and 30-41. RCW was higher in group P before implantation. Post-implantation RCW values were higher in group C, significantly at time points 19, 20, 32-34, 51-53, and 55-57. Continuous-flow pumps more effectively optimize RV function than pulsatile LVADs, which can result in more effective prevention of RV failure or insuffiency in that group. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. A novel vacuum assisted closure therapy model for use with percutaneous devices.

    Science.gov (United States)

    Cook, Saranne J; Nichols, Francesca R; Brunker, Lucille B; Bachus, Kent N

    2014-06-01

    Long-term maintenance of a dermal barrier around a percutaneous prosthetic device remains a common clinical problem. A technique known as Negative Pressure Wound Therapy (NPWT) uses negative pressure to facilitate healing of impaired and complex soft tissue wounds. However, the combination of using negative pressure with percutaneous prosthetic devices has not been investigated. The goal of this study was to develop a methodology to apply negative pressure to the tissues surrounding a percutaneous device in an animal model; no tissue healing outcomes are presented. Specifically, four hairless rats received percutaneous porous coated titanium devices implanted on the dorsum and were bandaged with a semi occlusive film dressing. Two of these animals received NPWT; two animals received no NPWT and served as baseline controls. Over a 28-day period, both the number of dressing changes required between the two groups as well as the pressures were monitored. Negative pressures were successfully applied to the periprosthetic tissues in a clinically relevant range with a manageable number of dressing changes. This study provides a method for establishing, maintaining, and quantifying controlled negative pressures to the tissues surrounding percutaneous devices using a small animal model. Published by Elsevier Ltd.

  6. A Functional Analysis Of An Assistive Device Information Database in Flanders: A Qualitative Study.

    Science.gov (United States)

    Cardinaels, Loes; Verbrugghe, Jonas; Haesen, Mieke; Schouten, Ben; Ceccarelli, Bianca; Timmermans, Annick; Spooren, Annemie

    2015-01-01

    Since 1989-1990, Vlibank is the Flemish AT information database managed by the Flemish government and aims to have a complete overview of AT devices in Flanders. The growing AT market increases the need for unbiased information on AT. However, maintaining and keeping a database up-to-date is a very challenging task. Because of recent changes in policy, the Flemish government needs to be able to reimburse a bigger group of AT devices, but also the changing needs of a larger group of people, regardless of their age. Because the crucial role of an AT information database in the selection of AT devices and the effectiveness of the service delivery, a functional analysis of an online information database is made. This paper describes the qualitative part of the study, in particular the focus groups that were held to gather views of three groups of stakeholders. Preliminary results indicate that there is consensus on the information needs next to product information and on the use of generic questions as a selection tool for AT devices. The biggest issue raised is the difficulty of keeping an information database up-to-date, especially for individualized devices. All participants, except one, are very wary of the use of user ratings and reviews.

  7. Machines versus medication for biventricular heart failure: focus on the total artificial heart.

    Science.gov (United States)

    Arabia, Francisco A; Moriguchi, Jaime D

    2014-09-01

    The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

  8. Amine-Assisted Delamination of Nb2C MXene for Li-Ion Energy Storage Devices.

    Science.gov (United States)

    Mashtalir, Olha; Lukatskaya, Maria R; Zhao, Meng-Qiang; Barsoum, Michel W; Gogotsi, Yury

    2015-06-17

    2D Nb2CTx MXene flakes are produced using an amine-assisted delamination process. Upon mixing with carbon nanotubes and filtration, freestanding, flexible paper is produced. The latter exhibits high capacity and excellent stability when used as the electrode for Li-ion batteries and capacitors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Quality of needs assessment for care and assistive devices from a client's perspective.

    NARCIS (Netherlands)

    Nispen, R.M.A. van; Sixma, H.J.; Kerkstra, A.

    2002-01-01

    Background: Like in many other European countries, health care policy makers in The Netherlands are looking for new ways to organize different health care services. To facilitate a more objective, independent and integral assessment for individuals in need of (nursing) home care or assistive

  10. Toxicity testing of human assisted reproduction devices using the mouse embryo assay.

    NARCIS (Netherlands)

    Punt-Van der Zalm, J.P.; Hendriks, J.C.M.; Westphal, J.R.; Kremer, J.A.M.; Teerenstra, S.; Wetzels, A.M.M.

    2009-01-01

    Systems to assess the toxicity of materials used in human assisted reproduction currently lack efficiency and/or sufficient discriminatory power. The development of 1-cell CBA/B6 F1 hybrid mouse embryos to blastocysts, expressed as blastocyst rate (BR), is used to measure toxicity. The embryos were

  11. The effects of electromagnetic radiation (2450 MHz wireless devices) on the heart and blood tissue: role of melatonin.

    Science.gov (United States)

    Gumral, N; Saygin, M; Asci, H; Uguz, A C; Celik, O; Doguc, D K; Savas, H B; Comlekci, S

    2016-01-01

    This study was designed to investigate the effects of 2450 MHz EMR on the heart and blood in rat and possible ameliorating effects of melatonin. Thirty-two female Wistar Albino rats were randomly grouped (by eight in each group) as follows:  Group I: cage-control group (dimethysulfoxide (DMSO), 10mg/kg/day i.p. without stress and EMR. Group II: sham-control rats stayed in restrainer without EMR and DMSO (10mg/kg/day i.p.). Group III: rats exposed to 2450 MHz EMR. Group IV: treated group rats exposed to 2450 MHz EMR+melatonin (MLT) (10mg/kg/day i.p.). In the blood tissue, there was no significant difference between the groups in respect of erythrocytes GSH, GSH-Px activity, plasma LP level and vitamin A concentration (p > 0.05). However, in the Group IV, erythrocytes' LP levels (p < 0.05) were observed to be significantly decreased while plasma vitamin C, and vitamin E concentrations (p < 0.05) were found to be increased when compared to Group III. In the heart tissues, MDA and NO levels significantly increased in group III compared with groups I and II (p < 0.05). Contrary to these oxidant levels, CAT and SOD enzyme activities decreased significantly in group III compared with groups I and II (p 0.05). Besides, MLT treatment lowered the MDA and NO levels compared with group III. In conclusion, these results demonstrated that contrary to its effect on the heart, the wireless (2450 MHz) devices cause slight oxidative-antioxidative changes in the blood of rats, and a moderate melatonin supplementation may play an important role in the antioxidant system (plasma vitamin C and vitamin E). However, further investigations are required to clarify the mechanism of action of the applied 2450 MHz EMR exposure (Tab. 3, Fig. 1, Ref. 49).

  12. Design and performance testing of an axial-flow ventricular assist device developed at the Fu Wai Hospital in Beijing.

    Science.gov (United States)

    Zhang, Y; Hu, S-S; Zhou, J-Y; Sun, H-S; Zhang, H; Zheng, Z; Zhu, X-D; Li, G-R; Gui, X-M; Zhan, Z; Jin, D-H

    2008-11-01

    Various ventricular assist devices (VADs) have been developed for clinical use in recent years. The aim of a multidisciplinary research team at the Fuwai Hospital of the Peking Union Medical College is to design and develop an axial flow left ventricular assist device (LVAD) for adults. Using Computational Fluid Dynamics (CFD), the inflow characteristics of the axial flow pump were analyzed. After CFD analysis, the axial pump was fabricated using a 5-axis, computer numerical control (CNC) milling machine. Performances of the pump both in vitro and in vivo were tested. This VAD, which was developed after numerous CFD analyses for the flow characteristics of the pump, is 58.5 mm long, 30 mm wide and weighs 120 g. The pump can deliver 5 lpm for pressures of 100 mmHg over 8500 rpm. The NIH value was 0.01 g/100 L. The hemolysis, which was evaluated in an in vivo test, was a bit higher than the normal value, but remained within an acceptable range. Performance of the pump in vitro and in vivo was considered sufficient for an LVAD. Further design improvements are being undertaken in terms of hemolysis and thrombosis to improve the biocompatibility of the pump.

  13. The effect of an on-body personal lift assist device (PLAD) on fatigue during a repetitive lifting task.

    Science.gov (United States)

    Lotz, Christy A; Agnew, Michael J; Godwin, Alison A; Stevenson, Joan M

    2009-04-01

    Occupations demanding frequent and heavy lifting are associated with an increased risk of injury. A personal lift assist device (PLAD) was designed to assist human muscles through the use of elastic elements. This study was designed to determine if the PLAD could reduce the level of general and local back muscle fatigue during a cyclical lifting task. Electromyography of two erector spinae sites (T9 and L3) was recorded during a 45-min lifting session at six lifts/lowers per minute in which male participants (n=10) lifted a box scaled to represent 20% of their maximum back extensor strength. The PLAD device reduced the severity of muscular fatigue at both muscle sites. RMS amplitude increased minimally (22% and 26%) compared to the no-PLAD condition (104% and 88%). Minimal median frequency decreases (0.33% and 0.41%) were observed in the PLAD condition compared to drops of 12% and 20% in the no-PLAD condition. The PLAD had an additional benefit of minimizing pre-post changes in muscular strength and endurance. The PLAD also resulted in a significantly lower rate of perceived exertion across the lifting session. It was concluded that the PLAD was effective at decreasing the level of back muscular fatigue.

  14. Engineered embodiment: Comment on "The embodiment of assistive devices-from wheelchair to exoskeleton" by M. Pazzaglia and M. Molinari

    Science.gov (United States)

    Kannape, Oliver Alan; Lenggenhager, Bigna

    2016-03-01

    From brain-computer interfaces to wearable robotics and bionic prostheses - intelligent assistive devices have already become indispensable in the therapy of people living with reduced sensorimotor functioning of their physical body, be it due to spinal cord injury, amputation or brain lesions [1]. Rapid technological advances will continue to fuel this field for years to come. As Pazzaglia and Molinari [2] rightly point out, progress in this domain should not solely be driven by engineering prowess, but utilize the increasing psychological and neuroscientific understanding of cortical body-representations and their plasticity [3]. We argue that a core concept for such an integrated embodiment framework was introduced with the formalization of the forward model for sensorimotor control [4]. The application of engineering concepts to human movement control paved the way for rigorous computational and neuroscientific analysis. The forward model has successfully been adapted to investigate principles underlying aspects of bodily awareness such as the sense of agency in the comparator framework [5]. At the example of recent advances in lower limb prostheses, we propose a cross-disciplinary, integrated embodiment framework to investigate the sense of agency and the related sense of body ownership for such devices. The main onus now is on the engineers and cognitive scientists to embed such an approach into the design of assistive technology and its evaluation battery.

  15. New biomedical devices that use near-infrared technology to assist with phlebotomy and vascular access.

    Science.gov (United States)

    Yen, Kenneth; Gorelick, Marc H

    2013-03-01

    Obtaining intravenous access in children is often challenging. Devices using the novel technology of near-infrared imaging have been developed and marketed to facilitate intravenous catheter placement and phlebotomy. We review the technology of near-infrared imaging and the evidence for its use in the pediatric emergency population.

  16. Splenectomy revised: manually assisted splenectomy with the dexterity device--a feasibility study in 22 patients

    NARCIS (Netherlands)

    Meijer, D. W.; Gossot, D.; Jakimowicz, J. J.; de Wit, L. T.; Bannenberg, J. J.; Gouma, D. J.

    1999-01-01

    Laparoscopic splenectomy claims a number of advantages over open surgery: less trauma, quicker recovery, and faster return to normal activity. On the other hand, laparoscopic splenectomy is complex and time consuming, and so far, many surgeons are reluctant to perform such an operation. A new device

  17. CFD Design and Analysis of a Passively Suspended Tesla Pump Left Ventricular Assist Device

    Science.gov (United States)

    Medvitz, Richard B.; Boger, David A.; Izraelev, Valentin; Rosenberg, Gerson; Paterson, Eric G.

    2012-01-01

    This paper summarizes the use of computational fluid dynamics (CFD) to design a novelly suspended Tesla LVAD. Several design variants were analyzed to study the parameters affecting device performance. CFD was performed at pump speeds of 6500, 6750 and 7000 RPM and at flow rates varying from 3 to 7 liter-per-minute (LPM). The CFD showed that shortening the plates nearest the pump inlet reduced the separations formed beneath the upper plate leading edges and provided a more uniform flow distribution through the rotor gaps, both of which positively affected the device hydrodynamic performance. The final pump design was found to produce a head rise of 77 mmHg with a hydraulic efficiency of 16% at the design conditions of 6 LPM throughflow and a 6750 RPM rotation rate. To assess the device hemodynamics the strain rate fields were evaluated. The wall shear stresses demonstrated that the pump wall shear stresses were likely adequate to inhibit thrombus deposition. Finally, an integrated field hemolysis model was applied to the CFD results to assess the effects of design variation and operating conditions on the device hemolytic performance. PMID:21595722

  18. Design and Implementation of NTU Wearable Exoskeleton as an Enhancement and Assistive Device

    OpenAIRE

    Low, K.H.; Liu, X.; Yu, H.

    2006-01-01

    This article presents a wearable lower extremity exoskeleton (LEE) developed to enhance the ability of a human’s walking while carrying heavy loads. The ultimate goal of the current research work is to design and control a power assist system that integrates a human’s intellect for feedback and sensory purposes. The exoskeleton system in this work consists of an inner exoskeleton and an outer exoskeleton. The inner exoskeleton measures the movements of the wearer and provides these measuremen...

  19. Essential elements for assessment of persons with severe neurological impairments for computer access utilizing assistive technology devices: a Delphi study.

    Science.gov (United States)

    Hoppestad, Brian Scott

    2006-01-01

    The objective of this study was to determine prospective elements that should comprise a comprehensive and valid assessment of persons with severe disabilities for access to computers utilizing assistive technology (AT). Currently, there is a lack of guidelines regarding areas that permit a satisfactory measure of a person's need for AT devices to enable computer access, resulting in substandard services. A list of criteria for elements that should be incorporated into an instrument for determining AT for computer access was compiled from a literature review in the areas of neuroscience, rehabilitation, and education; and a Delphi study using an electronic survey form that was e-mailed to a panel of experts in the field of AT. Only those areas rated as essential to the assessment process ('very important' or 'important' by 80% of the respondents) were chosen as important criteria for an assessment instrument. The initial Delphi survey contained 22 categories (54 subcategories or elements) for incorporation into an assessment for computer access. The second round of the survey completed the Delphi process resulting in a consensus for inclusion of 39 of the elements in an assessment instrument. There are inherent obstacles to prescribing the proper AT device to assist disabled persons with computer access due to the complexity of his/her condition, and the multitude of technological devices available to aid persons in accomplishing diverse tasks